cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A004740 Integers in alphabetical order in U.S. English.

Original entry on oeis.org

8, 8000000000, 8000000008, 8000000018, 8000000080, 8000000088, 8000000085
Offset: 1

Views

Author

N. J. A. Sloane, Neil Fernandez

Keywords

Comments

Jasper Mulder, Jan 25 2010, comments that this sequence is ill-defined, since there are an infinite number of cardinal numbers that start with a 'd', namely all those powers of 10 named decillion, duodecillion and so on (see http://en.wikipedia.org/wiki/English_numerals).
However, it would seem then that 'billion' and 'centillion' also precede these, while it is standard (and systematic for this sequence) to refer to such numbers as 'one billion', 'one decillion', etc. - Yasiru Ratnayake, May 03 2012

Examples

			The list begins "eight", "eight billion", "eight billion eight", ... [corrected by _Paul Duckett_, Nov 26 2023]

References

  • F. Smarandache, Sequences of Numbers Involved in Unsolved Problems, Hexis, Phoenix, 2006.

Links

Crossrefs

Cf. A019440, A026081. See A108067 for another version.
Cf. A073327, A152611, A075831, A000052.

A005606 Position of first letter of n (in English) in alphabet.

Original entry on oeis.org

26, 15, 20, 20, 6, 6, 19, 19, 5, 14, 20, 5, 20, 20, 6, 6, 19, 19, 5, 14, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19
Offset: 0

Views

Author

N. J. A. Sloane

Keywords

Comments

English name for n begins with a(n)-th letter.

Examples

			'One' begins with 'O' and 'O' is the fifteenth letter hence a(1)=15.

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Programs

  • Mathematica
    Table[LetterNumber[Characters[IntegerName[n,"Words"]][[1]]],{n,0,80}] (* Harvey P. Dale, Jun 06 2016 *)
  • Python
    from num2words import num2words
def a(n): return ord(num2words(n)[0]) - 96
print([a(n) for n in range(78)]) # Michael S. Branicky, Jul 12 2022

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Oct 02 2000

A008519 Numbers whose American English name contains the letter 'o'.

Original entry on oeis.org

0, 1, 2, 4, 14, 21, 22, 24, 31, 32, 34, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 54, 61, 62, 64, 71, 72, 74, 81, 82, 84, 91, 92, 94, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Cf. A008520 (e), A008522 (t), A008536 (n), A008538 (s), A008540 (f), A008553 (y).

Programs

  • Mathematica
    A008519Q[n_]:=StringContainsQ[IntegerName[n,"Words"],"o"];Select[Range[0,200],A008519Q] (* Paolo Xausa, Aug 10 2023 *)

Extensions

Name edited by Paolo Xausa, Aug 12 2023

A008538 Numbers whose American English name contains the letter 's'.

Original entry on oeis.org

6, 7, 16, 17, 26, 27, 36, 37, 46, 47, 56, 57, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 86, 87, 96, 97, 106, 107, 116, 117, 126, 127, 136, 137, 146, 147, 156, 157, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Cf. A008519 (o), A008520 (e), A008522 (t), A008536 (n), A008540 (f), A008553 (y).

Programs

  • Mathematica
    A008538Q[n_]:=StringContainsQ[IntegerName[n,"Words"],"s"];Select[Range[0,200],A008538Q] (* Paolo Xausa, Aug 12 2023 *)

Extensions

Name edited by Paolo Xausa, Aug 12 2023

A008540 Numbers whose American English name contains the letter 'f'.

Original entry on oeis.org

4, 5, 14, 15, 24, 25, 34, 35, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 64, 65, 74, 75, 84, 85, 94, 95, 104, 105, 114, 115, 124, 125, 134, 135, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Cf. A008519 (o), A008520 (e), A008522 (t), A008536 (n), A008538 (s), A008553 (y).

Programs

  • Mathematica
    A008540Q[n_]:=StringContainsQ[IntegerName[n,"Words"],"f"];Select[Range[0,200],A008540Q] (* Paolo Xausa, Aug 12 2023 *)

Extensions

Name edited by Paolo Xausa, Aug 12 2023

A008553 Numbers whose American English name contains the letter 'y'.

Original entry on oeis.org

20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Cf. A008519 (o), A008520 (e), A008522 (t), A008536 (n), A008538 (s), A008540 (f).

Programs

  • Mathematica
    A008553Q[n_]:=StringContainsQ[IntegerName[n,"Words"],"y"];Select[Range[0,200],A008553Q] (* Paolo Xausa, Aug 12 2023 *)

Extensions

Name edited by Paolo Xausa, Aug 12 2023

A011762 Number of letters in n (in Spanish).

Original entry on oeis.org

4, 3, 3, 4, 6, 5, 4, 5, 4, 5, 4, 4, 4, 5, 7, 6, 9, 10, 9, 10, 6, 9, 9, 10, 12, 11, 10, 11, 10, 11, 7, 11, 11, 12, 14, 13, 12, 13, 12, 13, 8, 12, 12, 13, 15, 14, 13, 14, 13, 14, 9, 13, 13, 14, 16, 15, 14, 15, 14, 15, 7, 11, 11, 12, 14, 13, 12, 13, 12, 13, 7, 11, 11, 12, 14, 13, 12, 13, 12
Offset: 0

Views

Author

Juan-Carlos Lerman (jclerm(AT)aztec.asu.edu)

Keywords

Comments

Spaces are ignored.

Links

Programs

  • Mathematica
    Table[Length[Select[Characters[IntegerName[n,{"Spanish"}]],LetterQ]],{n,0,78}] (* James C. McMahon, Mar 31 2024 *)

Extensions

Extended by Ray Chandler, Jul 16 2009

A037196 Number of vowels in the American English name of n.

Original entry on oeis.org

2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 1, 3, 2, 3, 4, 3, 3, 4, 4, 4, 1, 3, 2, 3, 3, 3, 2, 3, 3, 3, 1, 3, 2, 3, 3, 3, 2, 3, 3, 3, 1, 3, 2, 3, 3, 3, 2, 3, 3, 3, 1, 3, 2, 3, 3, 3, 2, 3, 3, 3, 1, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 4, 3, 4, 4, 4, 3, 4, 4, 4, 2, 4, 3, 4, 4, 4, 3, 4, 4, 4, 2, 4, 3, 4, 4, 4, 3, 4, 4, 4, 4, 6, 5, 6, 6
Offset: 0

Views

Author

N. J. A. Sloane

Keywords

Comments

"American English" means that there is no "and" in the names of numbers, cf. example. - M. F. Hasler, Aug 26 2020

Examples

			a(20) = 1 for "twEnty" with 1 vowel: 'y' does not count.
a(101) = 6 for "OnE hUndrEd OnE" with 6 vowels: no "and" as in the "British" variant "one hundred and one" which would have 7 vowels.

Crossrefs

Cf. A005589, A052360 (number of letters in English name of numbers with/without spaces and dashes).
Sequences related to vowels: A102869, A158352, A158354 (smallest number with n [distinct] vowels in AE / BE), A158353, A158355 (ditto, increasing), A058179 (all 5 vowels), A058180 (ditto, exactly once), A000852, A000861 (start/end with vowel), A019270, A080518 (self-describing), A059437, A079741, A152592, A174879, A241858, A332068, A332069.

Programs

  • PARI
    vowels=Vec("aeiou"); apply( {A037196(n)=#[c|c<-Vec(English(n)),setsearch(vowels,c)]}, [0..104]) \\ see A052360 for English(). - M. F. Hasler, Aug 26 2020
  • Python
    from num2words import num2words
def a(n): return sum(1 for c in num2words(n).replace(" and", "") if c in "aeiou")
print([a(n) for n in range(105)]) # Michael S. Branicky, Mar 23 2025

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Sep 25 2000
Name edited and crossrefs added by M. F. Hasler, Aug 26 2020
a(19)=4 corrected by Sean A. Irvine, Dec 16 2020

A060403 Each term is the previous term plus the number of letters in the previous number, as conventionally spelled out in American English.

Original entry on oeis.org

1, 4, 8, 13, 21, 30, 36, 45, 54, 63, 73, 85, 95, 105, 119, 137, 158, 178, 200, 210, 223, 244, 263, 283, 304, 320, 338, 361, 381, 402, 416, 434, 455, 475, 497, 519, 538, 560, 576, 597, 619, 637, 658, 678, 700, 712, 730, 748, 770, 789, 811, 829, 851, 871, 893
Offset: 1

Views

Author

Kevin Langdon (kevin.langdon(AT)polymath-systems.com), Apr 05 2001

Keywords

Comments

Increases more slowly than A160395 since American English does not use 'and' to separate hundreds from the rest of the number. E.g., 619 = "six hundred nineteen" in American English but "six hundred and nineteen" in British English. - Carl R. White, May 12 2009

Examples

			a(2)=4 because a(1)=1 and 4 is 1 plus the number of letters in "one," 3.

References

  • GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See pages 49 and 214.

Links

Crossrefs

Cf. A005589 See A139097 for another version.
For British English see A160395. - Carl R. White, May 12 2009

Programs

  • Mathematica
    NestList[#+Length[Select[Characters[IntegerName[#,"Words"]],LetterQ ]]&,1,54] (* James C. McMahon, Jul 30 2024 *)

Extensions

More terms from Carl R. White, May 12 2009

A079741 Numbers ending with a vowel or the letter y in American English.

Original entry on oeis.org

0, 1, 2, 3, 5, 9, 12, 20, 21, 22, 23, 25, 29, 30, 31, 32, 33, 35, 39, 40, 41, 42, 43, 45, 49, 50, 51, 52, 53, 55, 59, 60, 61, 62, 63, 65, 69, 70, 71, 72, 73, 75, 79, 80, 81, 82, 83, 85, 89, 90, 91, 92, 93, 95, 99, 101, 102, 103, 105, 109, 112, 120, 121, 122, 123, 125, 129, 130
Offset: 1

Views

Author

Hollie L. Buchanan II, Feb 17 2003

Keywords

Crossrefs

Cf. A000861.

Extensions

More terms from Robert G. Wilson v, Mar 13 2003
0 inserted by Sean A. Irvine, Aug 25 2025
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Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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