# 400 (number)

**400** (**four hundred**) is the natural number following 399 and preceding 401.

| ||||
---|---|---|---|---|

Cardinal | four hundred | |||

Ordinal | 400th (four hundredth) | |||

Factorization | 2^{4} × 5^{2} | |||

Divisors | 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400 | |||

Greek numeral | Υ´ | |||

Roman numeral | CD | |||

Binary | 110010000_{2} | |||

Ternary | 112211_{3} | |||

Quaternary | 12100_{4} | |||

Quinary | 3100_{5} | |||

Senary | 1504_{6} | |||

Octal | 620_{8} | |||

Duodecimal | 294_{12} | |||

Hexadecimal | 190_{16} | |||

Vigesimal | 100_{20} | |||

Base 36 | B4_{36} | |||

Hebrew | ת (Tav) |

## Mathematical propertiesEdit

400 is the square of 20. 400 is the sum of the powers of 7 from 0 to 3, thus making it a repdigit in base 7 (1111).

A circle is divided into 400 grads, which is equal to 360 degrees and 2π radians. (Degrees and radians are the SI accepted units).

400 is a self number in base 10, since there is no integer that added to the sum of its own digits results in 400. On the other hand, 400 is divisible by the sum of its own base 10 digits, making it a Harshad number.

## Other fieldsEdit

**Four hundred** is also

- The Four Hundred (oligarchy) of ancient Athens.
- An HTTP status code for a bad client request.
- The Four Hundred (sometimes The Four Hundred Club) a phrase meaning the wealthiest, most famous, or most powerful social group (see, e.g., Ward McAllister), leading to the generation of such lists as the Forbes 400.
- The Atari 400 home computer.
- A former limited stop bus route which operated from Bolton to Stockport and Manchester Airport from 1970 to 2004, known as the Trans-Lancs Express.
- in the title of the film
*Les Quatre Cent Coups*(*The 400 Blows*), a French film directed by François Truffaut. - A Lebanese card game. 400 (card game)
- the designation for a class of Ontario highways called 400-Series Highways.
- The 400, later the Twin Cities 400, a Chicago and North Western Railway passenger train that traveled 400 miles between Minneapolis/St. Paul and Chicago, Illinois in 400 minutes.
- The yard number of the RMS
*Olympic*, the RMS*Titanic*'s sister ship. - .400 (2 hits out of 5 at-bats) is a numerically significant annual batting average statistic in Major League Baseball, last accomplished by Ted Williams of the Boston Red Sox in 1941.
- The number of days in a Gregorian calendar year changes according to a cycle of exactly 400 years, of which 97 are leap years and 303 are common.
- The Intertestamental period or period of time between the writings of the Hebrew Bible and the Christian New Testament texts is traditionally considered to be a roughly four hundred-year period.
- The Sun is approximately 400 times the size of the Moon but also is approximately 400 times further away, creating the temporary illusion in which the Sun and Moon in Earth's sky appear as if of similar size.
- In gematria 400 is the largest single number that can be represented without using the Sophit forms (see Kaph, Mem, Nun, Pe, and Tzade).

## Integers from 401 to 499Edit

### 400sEdit

#### 401Edit

A prime number, tetranacci number,^{[1]} sum of seven consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71), sum of nine consecutive primes (29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61), Chen prime,^{[2]} Eisenstein prime with no imaginary part, Mertens function returns 0,^{[3]} member of the Mian–Chowla sequence.^{[4]}

- HTTP status code for "Unauthorized", area code for Rhode Island, also in the name of a retirement plan, 401(k). Stephen Colbert's
**Formula 401**, a "man seed" based product brand his persona on*The Colbert Report*promotes for sale to the public [1]. - Ontario Highway 401, colloquially referred to as the four-oh-one, is a popular Canadian highway 817.9 kilometres (508.2 mi) that stretches from Windsor to the Quebec border, passing through Toronto. It turns into Quebec Autoroute 20 at the Quebec/Ontario border which leads to the cities of Montreal and Quebec.

#### 402Edit

402 = 2 × 3 × 67, sphenic number, nontotient, Harshad number,

- HTTP status code for "Payment Required", area code for Nebraska

#### 403Edit

403 = 13 × 31, Mertens function returns 0.^{[3]}

- First number that is the product of an emirp pair.
^{[5]} - HTTP status code for "Forbidden"
- Also in the name of a retirement plan in the United States, 403(b).
- The area code for southern Alberta.

#### 404Edit

404 = 2^{2} × 101, Mertens function returns 0,^{[3]} nontotient, noncototient.

- HTTP status code for "Not Found", perhaps the most famous HTTP status code.
- Section
**404**of the Sarbanes–Oxley Act. - One of the three area codes of the Atlanta calling area.

#### 405Edit

405 = 3^{4} × 5, Mertens function returns 0,^{[3]} Harshad number;

- HTTP status code for "Method Not Allowed".
- Area code for central Oklahoma, including Oklahoma City and surrounding suburbs.

#### 406Edit

Wikisource has original text related to this article: |

406 = 2 × 7 × 29, sphenic number, triangular number, centered nonagonal number,^{[6]} nontotient

- HTTP status code for "Not Acceptable".
*406*is a poem by John Boyle O'Reilly. It was believed to have been the number of one of O'Reilly's prison cells, and was the number of his first hotel room after he arrived in the United States. Hence the number had a mystical significance to him, as intimated in the poem.- See also the Peugeot 406 car.
- Area code for all of Montana.

#### 407Edit

407 = 11 × 37,

- sum of cubes of 4, 0 and 7 (4
^{3}+ 0^{3}+ 7^{3}= 407); narcissistic number^{[7]} - sum of three consecutive primes (131 + 137 + 139)
- Mertens function returns 0
^{[3]} - Harshad number
- HTTP status code for "Proxy Authentication Required"
- Area code for Orlando, Florida
- Colloquial name for the Express Toll Route in Ontario

#### 408Edit

408 = 2^{3} × 3 × 17

- Sum of four consecutive primes (97 + 101 + 103 + 107)
- Sum of eight consecutive primes (37 + 41 + 43 + 47 + 53 + 59 + 61 + 67)
- Pell number
^{[8]} - Mertens function returns 0
^{[3]} - Octagonal number
^{[9]} - Untouchable number
^{[10]} - Harshad number
- HTTP status code for "Request Timeout"
- Area code for the Silicon Valley

#### 409Edit

409 is a prime number, Chen prime,^{[2]} centered triangular number.^{[11]}

- A family of cleaning products, Formula 409
- An engine known as the Chevrolet 409, a 409 cubic inch W-series V8.
- The song "409" by The Beach Boys, inspired by the above engine
- HTTP status code for "Conflict"
- A
*Green Day*song,*409 in Your Coffeemaker*, included on their album 1,039/Smoothed Out Slappy Hours - The area code for a part of eastern Texas
- Venice has 409 bridges.
^{[12]} - A
*Bullet For My Valentine*song, "Room 409", from the album The Poison - Joe Paterno holds the record as the winningest head coach in NCAA FBS with 409 victories.

### 410sEdit

#### 410Edit

410 = 2 × 5 × 41, sphenic number, sum of six consecutive primes (59 + 61 + 67 + 71 + 73 + 79), nontotient, Harshad number

- HTTP status code for "Gone".
- Area Code 410, a telephone area code for the US State of Maryland, representing portions of the state including the Baltimore metropolitan area and the Eastern Shore.

#### 411Edit

411 = 3 × 137, self number,^{[13]}

- HTTP status code for "Length Required", slang for information (see 4-1-1)
- The number of possible FM broadcasting frequencies between 87.50 and 108.00 MHz in 50 kHz spacing countries
^{[importance?]}

#### 412Edit

412 = 2^{2} × 103, nontotient, noncototient, sum of twelve consecutive primes (13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59)

- HTTP status code for "Precondition Failed"
- Area code for Pittsburgh, Pennsylvania.
- Fictitious Police Code for "Overacting" from "St. George and the Dragonet" - Stan Freeberg

#### 413Edit

413 = 7 × 59, Mertens function returns 0,^{[3]} self number^{[13]}

- HTTP status code for "Request Entity Too Large"
- Area code for Western Massachusetts.

#### 414Edit

414 = 2 × 3^{2} × 23, Mertens function returns 0,^{[3]} nontotient, Harshad number

- HTTP status code for "Request-URI Too Long"
- Area code for Milwaukee, Wisconsin.
- The 414s, a group of hackers from Milwaukee, Wisconsin.

#### 415Edit

415 = 5 × 83,

- HTTP status code for "Unsupported Media Type"
- 415 Records, a record label
- 415 refers to California Penal Code, section 415, pertaining to public fighting, public disturbance, and public use of offensive words likely to provoke an immediate violent reaction.
- Area code 415, a telephone area code for San Francisco, California

#### 416Edit

416 = 2^{5} × 13

- HTTP status code for "Requested Range Not Satisfiable"
- 416 is also a nickname for the city of Toronto, based on the area code it used before overlay plans added two more area codes.

#### 417Edit

417 = 3 × 139

- HTTP status code for "Expectation Failed". Also the area code for southwestern Missouri, including Springfield, and Joplin.

#### 418Edit

418 = 2 × 11 × 19, sphenic number,

- the number of Abrahadabra
- Hyper Text Coffee Pot Control Protocol status code for "Teapot" as an April Fools' joke.
^{[14]}^{[15]}

#### 419Edit

A prime number, Sophie Germain prime,^{[16]} Chen prime, Eisenstein prime with no imaginary part, highly cototient number,^{[17]} Mertens function returns 0^{[3]}

- refers to the Nigerian advance fee fraud scheme (after the section of the Nigerian Criminal Code it violates)

### 420sEdit

#### 420Edit

#### 421Edit

- A prime number, sum of five consecutive primes (73 + 79 + 83 + 89 + 97), centered square number,
^{[18]}also SMTP code meaning the transmission channel will be closing - Country calling code for Slovakia

#### 422Edit

422 = 2 × 211, Mertens function returns 0,^{[3]} nontotient

#### 423Edit

423 = 3^{2} × 47, Mertens function returns 0,^{[3]} Harshad number

- Country calling code for Liechtenstein

#### 424Edit

424 = 2^{3} × 53, sum of ten consecutive primes (23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61), Mertens function returns 0,^{[3]} refactorable number,^{[19]} self number^{[13]}

#### 425Edit

425 = 5^{2} × 17, pentagonal number,^{[20]} sum of three consecutive primes (137 + 139 + 149), Mertens function returns 0,^{[3]} the second number that can be expressed as the sum of two squares in three different ways (425 = 20^{2} + 5^{2} = 19^{2} + 8^{2} = 16^{2} + 13^{2} ).

- 425 is an area code in Washington State.

#### 426Edit

426 = 2 × 3 × 71, sphenic number, nontotient,

#### 427Edit

427 = 7 × 61, Mertens function returns 0^{[3]}

#### 428Edit

428 = 2^{2} × 107, Mertens function returns 0, nontotient

*428: Shibuya Scramble*, a video game

#### 429Edit

429 = 3 × 11 × 13, sphenic number, Catalan number^{[21]}

### 430sEdit

#### 430Edit

430 = 2 × 5 × 43, sphenic number, untouchable number^{[10]}

#### 431Edit

A prime number, Sophie Germain prime,^{[16]} sum of seven consecutive primes (47 + 53 + 59 + 61 + 67 + 71 + 73), Chen prime, Eisenstein prime with no imaginary part

- It is also the fourth Leyland prime of the second kind.
- The distance between Earth and the star Polaris in light years.
- Area code 431 is a telephone area code for Manitoba, Canada.

#### 432Edit

432 = 2^{4} × 3^{3} = 4^{2} × 3^{3}, The sum of four consecutive primes (103 + 107 + 109 + 113), a highly totient number,^{[22]} sum of totient function for first 37 integers. 432! is the first factorial that is not a Harshad number in base 10. 432 is also three-dozen sets of a dozen, making it three gross. An equilateral triangle whose area and perimeter are equal, has an area (and perimeter) equal to .

#### 433Edit

A prime number, Markov number,^{[23]} star number.^{[24]}

- The perfect score in the game show
*Fifteen To One*, only ever achieved once in over 2000 shows. - 433 can refer to composer John Cage's composition 4′33″ (pronounced "Four minutes, thirty-three seconds" or just "Four thirty-three").

#### 434Edit

434 = 2 × 7 × 31, sphenic number, sum of six consecutive primes (61 + 67 + 71 + 73 + 79 + 83), nontotient

#### 435Edit

435 = 3 × 5 × 29, sphenic number, triangular number, hexagonal number,^{[25]} self number^{[13]}

#### 436Edit

436 = 2^{2} × 109, nontotient, noncototient

#### 437Edit

437 = 19 × 23

#### 438Edit

438 = 2 × 3 × 73, sphenic number, Smith number.^{[26]}

- The "438 match" or "438 game" has been used by cricket media to describe the famous 2006 One Day International in which Australia scored a world record 434 in their innings, only to see South Africa respond in their innings with 438.

#### 439Edit

A prime number, sum of three consecutive primes (139 + 149 + 151), sum of nine consecutive primes (31 + 37 + 41 + 43 + 47 + 53 + 59 + 61 + 67), strictly non-palindromic number^{[27]}

### 440sEdit

#### 440Edit

440 = 2^{3} × 5 × 11, the sum of the first seventeen prime numbers, Harshad number,

- in hertz, the standard frequency to which most orchestras tune the pitch A above middle C. A few orchestras tune slightly flatter or sharper than this.

#### 441Edit

441 = 3^{2} × 7^{2} = 21^{2}

- 441 is the sum of the cubes of the first 6 natural numbers (441 = 1
^{3}+ 2^{3}+ 3^{3}+ 4^{3}+ 5^{3}+ 6^{3}). - 441 is a centered octagonal number,
^{[28]}a refactorable number,^{[19]}and a Harshad number. - 441 is the number of squares on a Super Scrabble board.

#### 442Edit

442 = 2 × 13 × 17, sphenic number, sum of eight consecutive primes (41 + 43 + 47 + 53 + 59 + 61 + 67 + 71)

#### 443Edit

A prime number, Sophie Germain prime,^{[16]} Chen prime, Eisenstein prime with no imaginary part, Mertens function sets new low of -9, which stands until 659.

- In computing, it is the default port for HTTPS connections.

#### 444Edit

444 = 2^{2} × 3 × 37, refactorable number,^{[19]} Harshad number.

#### 445Edit

445 = 5 × 89

#### 446Edit

446 = 2 × 223, nontotient, self number^{[13]}

#### 447Edit

447 = 3 × 149

#### 448Edit

448 = 2^{6} × 7, untouchable number,^{[10]} refactorable number,^{[19]} Harshad number

#### 449Edit

A prime number, sum of five consecutive primes (79 + 83 + 89 + 97 + 101), Chen prime, Eisenstein prime with no imaginary part, Proth prime.^{[29]} Also the largest number whose factorial is less than 10^{1000}

### 450sEdit

#### 450Edit

450 = 2 × 3^{2} × 5^{2}, nontotient, sum of totient function for first 38 integers, refactorable number,^{[19]} Harshad number,

- SMTP code meaning the requested mail action was not carried out.
- A perfect score in Canadian five-pin bowling.
- An area code in Southern Quebec.

#### 451Edit

451 = 11 × 41; 451 is a Wedderburn–Etherington number^{[30]} and a centered decagonal number;^{[31]} its reciprocal has period 10; 451 is the smallest number with this period reciprocal length.

- The novel
*Fahrenheit 451*refers to the temperature in Fahrenheit that author Ray Bradbury understood to be the autoignition point of paper. - HTTP status code for "Unavailable For Legal Reasons" a HTTP response error when the user requests an illegal resource, such as a web page censored by a government.
^{[32]}

#### 452Edit

452 = 2^{2} × 113

- SMTP code meaning that the requested mail action was not carried out because of insufficient system storage

#### 453Edit

453 = 3 × 151

#### 454Edit

454 = 2 × 227, nontotient, a Smith number^{[26]}

#### 455Edit

455 = 5 × 7 × 13, sphenic number, tetrahedral number^{[33]}

*455 Rocket*is the title of a song by Kathy Mattea- 455 kHz is a standard intermediate frequency for analog superheterodyne AM broadcast band receivers.

#### 456Edit

456 = 2^{3} × 3 × 19, sum of a twin prime (227 + 229), sum of four consecutive primes (107 + 109 + 113 + 127), centered pentagonal number^{[34]}

#### 457Edit

- A prime number, sum of three consecutive primes (149 + 151 + 157), self number.
^{[13]} - The international standard frequency for radio avalanche transceivers (457 kHz).

#### 458Edit

458 = 2 × 229, nontotient

#### 459Edit

459 = 3^{3} × 17

- 459 West 18th Street, a residential building at that address in Manhattan's West Chelsea neighborhood, built in 2008.

### 460sEdit

#### 460Edit

460 = 2^{2} × 5 × 23, centered triangular number,^{[11]} dodecagonal number,^{[35]} Harshad number, sum of twelve consecutive primes (17 + 19 + 23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61)

#### 461Edit

A prime number, Chen prime, sexy prime with 467, Eisenstein prime with no imaginary part

#### 462Edit

462 = 2 × 3 × 7 × 11, binomial coefficient , sum of six consecutive primes (67 + 71 + 73 + 79 + 83 + 89), pronic number,^{[36]} sparsely totient number^{[37]}

#### 463Edit

A prime number, sum of seven consecutive primes (53 + 59 + 61 + 67 + 71 + 73 + 79), centered heptagonal number,^{[38]}

- Number of days in the synodic period of Ceres
- A common baseball double play (see baseball positions)
- A single by Buck 65, named after the baseball term

#### 464Edit

464 = 2^{4} × 29, primitive abundant number^{[39]}

- In chess it is the number of legal positions of the kings, not counting mirrored positions. Has some importance when constructing an endgame tablebase.
*See also:*4-6-4, the year AD 464.

#### 465Edit

465 = 3 × 5 × 31, sphenic number, triangular number, member of the Padovan sequence,^{[40]} Harshad number

#### 466Edit

466 = 2 × 233, noncototient

#### 467Edit

A prime number, safe prime,^{[41]} sexy prime with 461, Chen prime, Eisenstein prime with no imaginary part

#### 468Edit

468 = 2^{2} × 3^{2} × 13, sum of ten consecutive primes (29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61 + 67), refactorable number,^{[19]} self number,^{[13]} Harshad number

#### 469Edit

469 = 7 × 67, centered hexagonal number^{[42]}

### 470sEdit

#### 470Edit

470 = 2 × 5 × 47, sphenic number, nontotient, noncototient

- In golf, 470 is the minimum length in yards from the tee to the hole on a Par 5.
- 470 is an Olympic class of sailing dinghy

#### 471Edit

471 = 3 × 157, sum of three consecutive primes (151 + 157 + 163), perfect totient number^{[43]}

#### 472Edit

472 = 2^{3} × 59, nontotient, untouchable number,^{[10]} refactorable number^{[19]}

#### 473Edit

473 = 11 × 43, sum of five consecutive primes (83 + 89 + 97 + 101 + 103)

#### 474Edit

474 = 2 × 3 × 79, sphenic number, sum of eight consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71 + 73), nontotient, noncototient, sum of totient function for first 39 integers, untouchable number,^{[10]} nonagonal number^{[44]}

#### 475Edit

475 = 5^{2} × 19, 49-gonal number, member of the Mian–Chowla sequence.^{[4]}

#### 476Edit

476 = 2^{2} × 7 × 17, Harshad number

#### 477Edit

477 = 3^{2} × 53, pentagonal number^{[20]}

#### 478Edit

478 = 2 × 239

#### 479Edit

A prime number, safe prime,^{[41]} sum of nine consecutive primes (37 + 41 + 43 + 47 + 53 + 59 + 61 + 67 + 71), Chen prime, Eisenstein prime with no imaginary part, self number^{[13]}

- Also an area code in the U.S. state of Arkansas.

### 480sEdit

#### 480Edit

480 = 2^{5} × 3 × 5, sum of a twin prime (239 + 241), sum of four consecutive primes (109 + 113 + 127 + 131), highly totient number,^{[22]} refactorable number,^{[19]} Harshad number

#### 481Edit

481 = 13 × 37, octagonal number,^{[9]} centered square number,^{[18]} Harshad number

#### 482Edit

482 = 2 × 241, nontotient, noncototient

#### 483Edit

483 = 3 × 7 × 23, sphenic number, Smith number^{[26]}

#### 484Edit

484 = 2^{2} × 11^{2} = 22^{2}, nontotient

#### 485Edit

485 = 5 × 97

#### 486Edit

486 = 2 × 3^{5}, Harshad number, Perrin number^{[45]}

- Shorthand for the Intel 80486 microprocessor chip.

#### 487Edit

A prime number, sum of three consecutive primes (157 + 163 + 167), Chen prime,

- The only primes under 7.74 × 10
^{13}that divide their own decimal repetends are 3, 487, and 56598313.^{[46]} - Shorthand for the Intel 80487 floating point processor chip.

#### 488Edit

488 = 2^{3} × 61, nontotient, refactorable number^{[19]}

#### 489Edit

489 = 3 × 163, octahedral number^{[47]}

### 490sEdit

#### 490Edit

490 = 2 × 5 × 7^{2}, noncototient, sum of totient function for first 40 integers, partition number (integer partitions of 19),^{[48]} self number.^{[13]}

- The Christian Gospel of Matthew (Matthew 18:21-22) says that Jesus told Peter to forgive his brother "seventy times seven" times when his brother sins against him [2].

#### 491Edit

A prime number, Sophie Germain prime,^{[16]} Chen prime, Eisenstein prime with no imaginary part, strictly non-palindromic number^{[27]}

#### 492Edit

492 = 2^{2} × 3 × 41, sum of six consecutive primes (71 + 73 + 79 + 83 + 89 + 97), refactorable number,^{[19]} member of a Ruth–Aaron pair with 493 under first definition

#### 493Edit

493 = 17 × 29, sum of seven consecutive primes (59 + 61 + 67 + 71 + 73 + 79 + 83), member of a Ruth–Aaron pair with 492 under first definition

#### 494Edit

494 = 2 × 13 × 19, sphenic number, nontotient

#### 495Edit

#### 496Edit

496 is the third perfect number, a number whose divisors add up to the actual number (1+2+4+8+16+31+62+124+248=496).

#### 497Edit

497 = 7 × 71, sum of five consecutive primes (89 + 97 + 101 + 103 + 107)

#### 498Edit

498 = 2 × 3 × 83, sphenic number, untouchable number,^{[10]} admirable number,^{[49]} abundant number

#### 499Edit

A prime number, Chen prime

## ReferencesEdit

**^**"Sloane's A000078 : Tetranacci numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.- ^
^{a}^{b}"Sloane's A109611 : Chen primes".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. - ^
^{a}^{b}^{c}^{d}^{e}^{f}^{g}^{h}^{i}^{j}^{k}^{l}^{m}^{n}"Sloane's A028442 : Numbers n such that Mertens' function is zero".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. - ^
^{a}^{b}"Sloane's A005282 : Mian-Chowla sequence".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. **^**Sloane, N. J. A. (ed.). "Sequence A083815".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation.**^**"Sloane's A060544 : Centered 9-gonal (also known as nonagonal or enneagonal) numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A005188 : Armstrong (or Plus Perfect, or narcissistic) numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A000129 : Pell numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.- ^
^{a}^{b}"Sloane's A000567 : Octagonal numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. - ^
^{a}^{b}^{c}^{d}^{e}^{f}"Sloane's A005114 : Untouchable numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. - ^
^{a}^{b}"Sloane's A005448 : Centered triangular numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. **^**Google Maps [@googlemaps] (16 June 2016). "117 islands, 150 canals, 409 bridges. Explore #Venice with this #GoogleMaps Trek" (Tweet) – via Twitter.- ^
^{a}^{b}^{c}^{d}^{e}^{f}^{g}^{h}^{i}"Sloane's A003052 : Self numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. **^**L. Masinter (1 April 1998). "Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)".*Network Working Group*(RFC). Retrieved 13 Sep 2018.Any attempt to brew coffee with a teapot should result in the error code "418 I'm a teapot". The resulting entity body MAY be short and stout.

**^**I. Nazar (1 April 2014). "The Hyper Text Coffee Pot Control Protocol for Tea Efflux Appliances (HTCPCP-TEA)" (RFC). ISSN 2070-1721. Retrieved 13 Sep 2018.TEA-capable pots that are not provisioned to brew coffee may return either a status code of 503, indicating temporary unavailability of coffee, or a code of 418 as defined in the base HTCPCP specification to denote a more permanent indication that the pot is a teapot.

- ^
^{a}^{b}^{c}^{d}"Sloane's A005384 : Sophie Germain primes".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. **^**"Sloane's A100827 : Highly cototient numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.- ^
^{a}^{b}"Sloane's A001844 : Centered square numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. - ^
^{a}^{b}^{c}^{d}^{e}^{f}^{g}^{h}^{i}^{j}"Sloane's A0033950 : Refactorable numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. - ^
^{a}^{b}"Sloane's A000326 : Pentagonal numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. **^**"Sloane's A000108 : Catalan numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.- ^
^{a}^{b}"Sloane's A097942 : Highly totient numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. **^**"Sloane's A002559 : Markoff (or Markov) numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A003154 : Centered 12-gonal numbers. Also star numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A000384 : Hexagonal numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.- ^
^{a}^{b}^{c}"Sloane's A006753 : Smith numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. - ^
^{a}^{b}"Sloane's A016038 : Strictly non-palindromic numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. **^**"Sloane's A016754 : Odd squares: a(n) = (2n+1)^2. Also centered octagonal numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A080076 : Proth primes".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A001190 : Wedderburn-Etherington numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A062786 : Centered 10-gonal numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**https://datatracker.ietf.org/doc/draft-ietf-httpbis-legally-restricted-status/**^**"Sloane's A000292 : Tetrahedral numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A005891 : Centered pentagonal numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A051624 : 12-gonal (or dodecagonal) numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A002378 : Oblong (or promic, pronic, or heteromecic) numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A036913 : Sparsely totient numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A069099 : Centered heptagonal numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A091191 : Primitive abundant numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A000931 : Padovan sequence".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.- ^
^{a}^{b}"Sloane's A005385 : Safe primes".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10. **^**"Sloane's A003215 : Hex (or centered hexagonal) numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A082897 : Perfect totient numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A001106 : 9-gonal (or enneagonal or nonagonal) numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A001608 : Perrin sequence".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A045616 : Primes p such that 10^(p-1) == 1 (mod p^2)".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2018-05-31.**^**"Sloane's A005900 : Octahedral numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A000041 : a(n) = number of partitions of n (the partition numbers)".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.**^**"Sloane's A111592 : Admirable numbers".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-06-10.