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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A008522 Numbers whose American English name contains the letter 't'.

Original entry on oeis.org

2, 3, 8, 10, 12, 13, 14, 15, 16, 17, 18, 19, 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
Offset: 1

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Author

Keywords

Examples

			8 = eigh{t}.
		

Crossrefs

Cf. A008519 (o), A008520 (e), A008536 (n), A008538 (s), A008540 (f), A008553 (y).

Programs

  • Mathematica
    A008522Q[n_]:=StringContainsQ[IntegerName[n,"Words"],"t"];Select[Range[0,200],A008522Q] (* Paolo Xausa, Aug 12 2023 *)

Extensions

Name edited by Paolo Xausa, Aug 12 2023

A052363 Numbers n whose English name has a greater length (A005589) than any smaller number.

Original entry on oeis.org

0, 3, 11, 13, 17, 23, 73, 101, 103, 111, 113, 117, 123, 173, 323, 373, 1103, 1111, 1113, 1117, 1123, 1173, 1323, 1373, 3323, 3373, 11373, 13323, 13373, 17373, 23323, 23373, 73373, 101373, 103323, 103373, 111373, 113323, 113373, 117373, 123323, 123373, 173373, 323373, 373373
Offset: 1

Views

Author

Allan C. Wechsler, Mar 07 2000

Keywords

Comments

Indices of records in A005589 (which only counts letters, but not spaces and punctuation, in the English name of numbers).

Examples

			Note that A052360(373373) = 64 and A005589(373373) = 56.
Sequence A052362 uses A052360 which also counts spaces and dashes, therefore "twenty-one" is in that sequence but not in this one: it uses one more character ('-') but has the same number of letters than "seventeen". - _M. F. Hasler_, Aug 12 2020
		

Crossrefs

Programs

  • PARI
    m=0; for(n=0, 2e6, if(m<A005589(n), m=A005589(n); print1(n", "))) \\ M. F. Hasler, Aug 12 2020
    
  • Python
    from itertools import count, islice
    from num2words import num2words as n2w
    def f(n): return sum(1 for c in n2w(n).replace(" and", "") if c.isalpha())
    def agen():
        record = 0
        for n in count(0):
            value = f(n)
            if value > record: yield n; record = value
            n += 1
    print(list(islice(agen(), 40))) # Michael S. Branicky, Jul 12 2022

Extensions

Edited by R. J. Mathar and T. D. Noe, Apr 09 2009
Minor edits by Ray Chandler, Jul 22 2009
a(41) and beyond from Michael S. Branicky, Jul 12 2022

A080777 a(n), when spelled in English, is the smallest positive integer with exactly n letters.

Original entry on oeis.org

1, 4, 3, 11, 15, 13, 17, 24, 23, 73, 101, 104, 103, 111, 115, 113, 117, 124, 123, 173, 323, 373, 1104, 1103, 1111, 1115, 1113, 1117, 1124, 1123, 1173, 1323, 1373, 3323, 3373, 11373, 13323, 13373, 17373, 23323, 23373, 73373, 101373, 103323, 103373, 111373
Offset: 3

Views

Author

Peter Kolbus (peter(AT)kolbusfamily.com), Mar 11 2003

Keywords

Comments

In this version 101 is written "one hundred one", etc.
This uses the conventions that "and" is never used and two-digit numbers are not used before "hundred". The sequence is labeled "finite" because there is no widely accepted naming convention for arbitrarily large numbers. - David Wasserman, Dec 20 2004

Examples

			The 3rd term has 5 letters; the smallest positive integer with this number of letters is 3 (three).
		

Crossrefs

Cf. A001166, A052196 (the 'largest' analog of this sequence), A084390.

Programs

  • Mathematica
    (* Works for a(n) up to 10^k *)
    k=5;name[n_]:=IntegerName[n,"Words"];
    nameLen[n_]:=StringLength[StringReplace[name[n],{" "-> "","-"-> "",","-> ""}]];
    max[n_]:=Max[nameLen/@Range[10^(n-1)+1,10^n]];max10toK=max/@Range[k];
    pos[n_Integer/;n>2]:=Position[Sort[Append[max10toK,n]],n,1][[1,1]]-1;
    a[n_Integer/;n>2&&n<(10^k)+1]:=Module[{l=10^pos[n]},While[nameLen[l]!=n,l++];l];
    a/@Range[3,40] (* Ivan N. Ianakiev, Sep 05 2018 *)

Extensions

Corrected by James Ong (blackshadowshade(AT)yahoo.com.au), Jun 27 2003
More terms from Brian Galebach, Feb 06 2004
Edited by David Wasserman, Dec 20 2004

A139282 Form a sequence of words as follows: look to the left, towards the beginning of the sequence and write down the number of vowels you see; repeat; then replace the words with the corresponding numbers.

Original entry on oeis.org

0, 2, 3, 5, 7, 9, 11, 14, 18, 22, 24, 27, 30, 31, 34, 37, 40, 41, 44, 47, 50, 51, 54, 57, 60, 61, 64, 67, 70, 72, 75, 79, 83, 87, 91, 95, 99, 103, 110, 116, 124, 132, 139, 147, 155, 163, 171, 180, 187, 196, 204, 210, 215, 222, 228, 235, 242, 248, 255, 262, 268, 275
Offset: 0

Views

Author

N. J. A. Sloane, Jun 08 2008

Keywords

Comments

The sequence of words is: zero, two, three, five, seven, nine, eleven, fourteen, ...
Hyphens and spaces are not counted.

Examples

			The second word is "two" (and so a(2)=2), because at the end of the first word we can see two vowels (the vowels in "zero") to the left.
		

References

  • E. Angelini, "Jeux de suites", in Dossier Pour La Science, pp. 32-35, Volume 59 (Jeux math'), April/June 2008, Paris.

Crossrefs

For a French version see A139212.

Extensions

Cross reference corrected by Sean A. Irvine, Mar 15 2010
More terms from Sean A. Irvine, Mar 15 2010

A380248 The order of the 13 cards of one suit such that after the SpellUnder-Down deal the cards are in order; a(n) is the n-th card in the deck.

Original entry on oeis.org

3, 8, 7, 1, 12, 6, 4, 2, 11, 13, 10, 9, 5
Offset: 1

Views

Author

Tanya Khovanova and the MIT PRIMES STEP junior group, Jan 17 2025

Keywords

Comments

Number 1 corresponds to ace, 11 to jack, 12 to queen, 13 to king.
In the SpellUnder-Down deal, we spell the next card, putting a card under for each letter in the name, then we deal the next card. So we start with putting 3 cards under for A-C-E, then deal, then 3 cards under for T-W-O, then deal, then 5 cards under for T-H-R-E-E, then deal. The dealing sequence is highly irregular because it depends on English spelling. The dealing pattern starts: UUUDUUUDUUUUUD.
The sequence is a permutation of 13 numbers.

Examples

			The first card dealt is the fourth card in the deck, thus, the fourth card must be an ace.
		

Crossrefs

A001166 Smallest natural number requiring n letters in English.

Original entry on oeis.org

1, 4, 3, 11, 15, 13, 17, 24, 23, 73, 3000, 11000, 15000, 101, 104, 103, 111, 115, 113, 117, 124, 123, 173, 323, 373, 1104, 1103, 1111, 1115, 1113, 1117, 1124, 1123, 1173, 1323, 1373, 3323, 3373, 11373, 13323, 13373, 17373, 23323, 23373, 73373, 101123, 101173, 101323, 101373, 103323, 103373, 111373, 113323, 113373, 117373
Offset: 3

Views

Author

Keywords

Comments

In this version 101 is written "one hundred and one", etc.

Examples

			For n = 6, the smallest natural number requiring 6 letters in English is "eleven." - _Julia Carrigan_, Jan 19 2024
		

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Extensions

Corrected and extended by Henry Bottomley, Jan 28 2000
Further corrected and extended by Brian Galebach, Feb 06 2004
Further corrected and illustration of terms by Sean A. Irvine, Mar 12 2012

A008536 Numbers whose American English name contains the letter 'n'.

Original entry on oeis.org

1, 7, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 37, 39, 41, 47, 49, 51, 57, 59, 61, 67, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 81, 87, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A008519 (o), A008520 (e), A008522 (t), A008538 (s), A008540 (f), A008553 (y).

Programs

  • Mathematica
    A008536Q[n_]:=StringContainsQ[IntegerName[n,"Words"],"n"];Select[Range[0,200],A008536Q] (* Paolo Xausa, Aug 12 2023 *)

Extensions

Name edited by Paolo Xausa, Aug 12 2023

A031139 Number of letters in English words for months of year.

Original entry on oeis.org

7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8, 7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8, 7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8, 7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8, 7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8, 7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8, 7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8
Offset: 1

Views

Author

Dmitri Papichev (Dmitri.Papichev(AT)iname.com)

Keywords

Comments

Period 12: repeat [7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8].
According to the definition this should strictly speaking be finite: there is no 13th month of the year. But for several reasons we prefer to see this as an infinite periodic sequence. - M. F. Hasler, Mar 05 2018

Examples

			a(1) = 7 because January has 7 letters.
		

References

  • GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 60.

Crossrefs

Programs

  • Mathematica
    PadRight[{}, 72, {7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8}] (* or *)
    Array[StringLength@ DateString[DateObject[{0, Mod[#, 12] + 1, 1, 0, 0, 0}, "Month"], {"MonthName"}] &, 72, 0] (* Michael De Vlieger, Feb 25 2018 *)
  • PARI
    A031139(n)=digits(879644355878)[12-n%12] \\ M. F. Hasler, Mar 05 2018

Formula

From Elmo R. Oliveira, Jul 18 2024: (Start)
G.f.: x*(7 + 8*x + 5*x^2 + 5*x^3 + 3*x^4 + 4*x^5 + 4*x^6 + 6*x^7 + 9*x^8 + 7*x^9 + 8*x^10 + 8*x^11)/(1 - x^12).
a(n) = a(n-12) for n > 12. (End)

A089589 Iban numbers (the letter i is banned from the English name of the number).

Original entry on oeis.org

0, 1, 2, 3, 4, 7, 10, 11, 12, 14, 17, 20, 21, 22, 23, 24, 27, 40, 41, 42, 43, 44, 47, 70, 71, 72, 73, 74, 77, 100, 101, 102, 103, 104, 107, 110, 111, 112, 114, 117, 120, 121, 122, 123, 124, 127, 140, 141, 142, 143, 144, 147, 170, 171, 172, 173, 174, 177, 200, 201
Offset: 1

Views

Author

Eric W. Weisstein, Nov 09 2003

Keywords

Comments

Blind numbers. - Cino Hilliard, May 03 2004
There are 30276 terms, ending in 777777. - Michael S. Branicky, Aug 04 2022

Crossrefs

Cf. A006933 (ban e), A008521 (ban o), A008523 (ban t), A089590 (ban u).

Programs

  • Haskell
    import Data.Maybe (fromJust)
    import Data.Text (Text); import qualified Data.Text as T (all)
    import Text.Numeral.Grammar.Reified (defaultInflection)
    import qualified Text.Numeral.Language.EN as EN  -- see link
    a089589 n = a089589_list !! (n-1)
    a089589_list = filter (T.all (/= 'i') . numeral) [0..] where
       numeral :: Integer -> Text
       numeral = fromJust . EN.gb_cardinal defaultInflection
    -- Reinhard Zumkeller, Jan 23 2015
    
  • Python
    from itertools import islice
    from num2words import num2words
    def agen(): yield from (k for k in range(10**6) if "i" not in num2words(k))
    print(list(islice(agen(), 60))) # Michael S. Branicky, Aug 04 2022

A000852 Numbers beginning with a vowel in English.

Original entry on oeis.org

1, 8, 11, 18, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132
Offset: 1

Views

Author

Keywords

Crossrefs

Previous Showing 51-60 of 824 results. Next