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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A067278 a(n) = letters(n) + a(n-1); a(0) = 0.

Original entry on oeis.org

0, 3, 6, 11, 15, 19, 22, 27, 32, 36, 39, 45, 51, 59, 67, 74, 81, 90, 98, 106, 112, 121, 130, 141, 151, 161, 170, 181, 192, 202, 208, 217, 226, 237, 247, 257, 266, 277, 288, 298, 303, 311, 319, 329, 338, 347, 355, 365, 375, 384, 389, 397, 405, 415, 424, 433, 441
Offset: 0

Views

Author

Scott A. Brown, Feb 22 2002

Keywords

Examples

			0 + one = 3, 3 + two = 6, 6 + three = 11, 11 + four = 15, 15 + five = 19, ....
		

Crossrefs

Formula

a(n) = A005589(n) + a(n-1). - Michael S. Branicky, Mar 03 2025

A163828 Number of straight line segments in all letters of the capitalized English name of n.

Original entry on oeis.org

9, 7, 6, 15, 5, 10, 3, 13, 12, 11, 9, 19, 18, 21, 18, 20, 16, 26, 23, 24, 18, 25, 24, 33, 23, 28, 21, 31, 30, 29, 13, 20, 19, 28, 18, 23, 16, 26, 25, 24, 10, 17, 16, 25, 15, 20, 13, 23, 22, 21, 12, 19, 18, 27, 17, 22, 15, 25, 24, 23, 8, 15, 14, 23, 13, 18, 11, 21, 20, 19, 18
Offset: 0

Views

Author

Jonathan Vos Post, Aug 05 2009

Keywords

Comments

Number of straight line segments (chisel strokes) in the capitalized English name of n (excluding spaces and hyphens), counting smooth curves as zero strokes.
The 15 letters which are entirely strokes (no curves): A(3), E(4), F(3), H(3), I(1), K(3), L(2), M(4), N(3), T(2), V(2), W(4), X(2), Y(3), Z(3).
Those 4 which are entirely curves (and count as zero): C, O, S, U.
Those 7 which mix strokes and curves: B(1), D(1), G(2), J(1), P(1), Q(1), R(2).
a(16)=16 is a fixed point.
The numbers written entirely from stroke-only letters are A163670.

Examples

			a(0) = 9 because ZERO has (letter by letter) 3+4+2+0 = 9 straight line segments (chisel strokes).
a(1) = 7 because ONE has 0+3+4 = 7 strokes.
a(20) = 18 because TWENTY (all strokes) has 2+4+4+3+2+3 = 18 strokes.
		

Crossrefs

Programs

  • Maple
    names :=["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine",
    "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen",
    "nineteen", "twenty", "twentyone", "twentytwo", "twentythree", "twentyfour", "twentyfive", "twentysix",
    "twentyseven", "twentyeight", "twentynine", "thirty", "thirtyone", "thirtytwo", "thirtythree",
    "thirtyfour", "thirtyfive", "thirtysix", "thirtyseven", "thirtyeight", "thirtynine", "forty",
    "fortyone", "fortytwo", "fortythree", "fortyfour", "fortyfive", "fortysix", "fortyseven",
    "fortyeight", "fortynine", "fifty", "fiftyone", "fiftytwo", "fiftythree", "fiftyfour",
    "fiftyfive", "fiftysix", "fiftyseven", "fiftyeight", "fiftynine", "sixty", "sixtyone",
    "sixtytwo", "sixtythree", "sixtyfour", "sixtyfive", "sixtysix", "sixtyseven", "sixtyeight",
    "sixtynine", "seventy", "seventyone", "seventytwo", "seventythree", "seventyfour",
    "seventyfive", "seventysix", "seventyseven", "seventyeight", "seventynine", "eighty",
    "eightyone", "eightytwo", "eightythree", "eightyfour", "eightyfive", "eightysix",
    "eightyseven", "eightyeight", "eightynine", "ninety", "ninetyone", "ninetytwo",
    "ninetythree", "ninetyfour", "ninetyfive", "ninetysix", "ninetyseven", "ninetyeight",
    "ninetynine", "onehundred"] :
    cstrok := [ 3, 1, 0, 1, 4, 3, 2, 3, 1, 1, 3, 2, 4, 3, 0, 1, 1, 2, 0, 2, 0, 2, 4, 2, 3, 3 ] ;
    A163828 := proc(n) global names, cstrok; a := 0 ; for c in StringTools[Explode]( names[n+1]) do a := a+ cstrok[StringTools[Ord](c)-96] ; od: a ; end:
    seq(A163828(n),n=0..70) ; # R. J. Mathar, Sep 29 2009

Extensions

a(36) changed to 16 by R. J. Mathar, Sep 29 2009

A233184 a(n) is the least number larger than the total number of letters in the English names for all terms up to and including a(n).

Original entry on oeis.org

5, 9, 16, 26, 35, 40, 49, 59, 66, 76, 86, 95, 109, 129, 149, 166, 186, 200, 209, 229, 249, 266, 286, 300, 316, 339, 359, 380, 399, 418, 439, 459, 480, 496, 510, 530, 546, 566, 586, 600, 609, 629, 649, 666, 686, 700, 716, 739, 759, 780, 799, 819, 840, 856, 879, 900, 905, 926, 945, 965, 986, 1000, 1010, 1030, 1046, 1066, 1086, 1110
Offset: 1

Views

Author

Eric Angelini and M. F. Hasler, Dec 05 2013

Keywords

Comments

See A233185-A233188 for French and German variants.

Programs

  • PARI
    a=0;k=0;for(n=1,99,until( k++ > a + A005589(k),); print1(k,","); a+=A005589(k))

A107322 English name for number and its reverse have the same number of letters.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 14, 22, 33, 34, 35, 38, 41, 43, 44, 45, 48, 53, 54, 55, 58, 66, 67, 69, 76, 77, 79, 83, 84, 85, 88, 96, 97, 99, 101, 102, 103, 104, 105, 106, 107, 108, 109, 111, 112, 113, 115, 118, 121, 122, 123, 124, 125, 126, 127, 128, 129, 131, 132
Offset: 0

Views

Author

David W. Wilson, May 21 2005

Keywords

Comments

Obviously includes all palindromes (A002113).

Examples

			35 is in sequence because 35 ("thirty-five") and 53 ("fifty-three") each have 10 letters in English (dashes not counted).
		

Crossrefs

Programs

  • Mathematica
    Select[Range[0,132],Length[Select[Characters[IntegerName[#,"Words"]],LetterQ]]==Length[Select[Characters[IntegerName[FromDigits[Reverse[IntegerDigits[#]]],"Words"]],LetterQ]]&] (* James C. McMahon, Feb 12 2024 *)
  • Python
    from num2words import num2words
    def n2w(n):
      map = {ord(c): None for c in "-, "}
      return num2words(n).replace(" and", "").translate(map)
    def ok(n): return len(n2w(n)) == len(n2w(int(str(n)[::-1])))
    print([k for k in range(133) if ok(k)]) # Michael S. Branicky, Feb 12 2024

Extensions

10 inserted by James C. McMahon, Feb 12 2024

A139097 Form a sequence of words as follows: look to the left, towards the beginning of the sequence and write down the number of letters you see; repeat; then replace the words with the corresponding numbers.

Original entry on oeis.org

0, 4, 8, 13, 21, 30, 36, 45, 54, 63, 73, 85, 95, 105, 119, 137, 158, 178, 200, 211, 227, 248, 268, 288, 309, 325, 347, 369, 390, 408, 424, 445, 465, 485, 506, 520, 537, 559, 579, 601, 614, 632, 651, 669, 688, 709, 725, 747, 769, 790, 808, 825, 847, 869, 890, 908, 924, 945, 965, 985, 1006, 1020, 1037, 1059
Offset: 0

Views

Author

Jonathan Vos Post, May 12 2007

Keywords

Comments

The sequence of words is: zero, four, eight, thirteen, twenty-one, thirty, ... (in American English).
Hyphens and spaces are not counted.
This is an English version of the sequence in A139121.
a(0) = 0, a(n+1) = a(n) + A005589(a(n)). - Jonathan Vos Post, Jun 15 2008

Examples

			The second word is "four" (and so a(2)=4), because at the end of the first word we can see four letters 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

Cf. A005589. See A060403 and A139121 for other versions.

Extensions

Edited by N. J. A. Sloane, Jun 08 2008
More terms from M. F. Hasler and R. J. Mathar, Jun 15 2008

A163670 Numbers whose English name (excluding spaces and hyphens) is written with only straight line segments (chisel strokes).

Original entry on oeis.org

5, 9, 10, 11, 12, 15, 19, 20, 25, 29, 50, 55, 59, 90, 95, 99
Offset: 1

Views

Author

Jonathan Vos Post, Aug 02 2009

Keywords

Comments

There are no elements in the sequence beyond 99 because of curves in writing hUnDReD, thOUSanD, milliOn, BilliOn, and so forth. If one counts the segments (chisel strokes) then 29 is the unique fixed point of that derived sequence.
Specifically, these are the numbers whose names use only the letters A, E, F, H, I, K, L, M, N, T, V, W, X, Y, and Z. [From Franklin T. Adams-Watters, Aug 06 2009]

Examples

			a(1) = 5 because FIVE is the smallest integer whose English name is written with only straight line segments. 6 is not in the sequence because the letter S has curves. a(2) = 9 because NINE is the next integer whose English name is written with only straight line segments.
		

Crossrefs

Extensions

Missing 55 and 95 added by Franklin T. Adams-Watters, Aug 06 2009
Slightly edited by Charles R Greathouse IV, Oct 05 2009

A241858 Positions of vowels in "one, two, three, four, five, six, ...".

Original entry on oeis.org

1, 3, 6, 10, 11, 13, 14, 17, 19, 21, 24, 26, 28, 29, 34, 36, 38, 40, 42, 44, 48, 51, 54, 57, 58, 61, 62, 65, 66, 69, 72, 73, 76, 79, 80, 83, 85, 88, 89, 91, 92, 96, 97, 100, 102, 104, 105, 109, 115, 119, 121, 124, 130, 133, 140, 141, 144, 149, 150, 154, 159, 161, 164, 169
Offset: 1

Views

Author

J. Lowell, Apr 30 2014

Keywords

Comments

Consider only letters, but not spaces or punctuation.

Examples

			The letters in "four" are the twelfth through fifteenth letters in "one, two, three, four, five, six, ...". The o and u, which are 13 and 14, are vowels.
		

Crossrefs

Programs

  • PARI
    A241858_vec(N,v=Vec("aeiou"),n,s,p,o)=vector(N,j, until( setsearch(v,s[p-o]), o+#s"@"]); p) \\ see A052360 for English(). - M. F. Hasler, Aug 11 2020

Extensions

More terms from Alois P. Heinz, Apr 30 2014
a(62)-a(64) from M. F. Hasler, Aug 11 2020

A362123 Number of letters in the British English name of n, excluding spaces and hyphens.

Original entry on oeis.org

4, 3, 3, 5, 4, 4, 3, 5, 5, 4, 3, 6, 6, 8, 8, 7, 7, 9, 8, 8, 6, 9, 9, 11, 10, 10, 9, 11, 11, 10, 6, 9, 9, 11, 10, 10, 9, 11, 11, 10, 5, 8, 8, 10, 9, 9, 8, 10, 10, 9, 5, 8, 8, 10, 9, 9, 8, 10, 10, 9, 5, 8, 8, 10, 9, 9, 8, 10, 10, 9, 7, 10, 10, 12, 11, 11, 10, 12, 12, 11, 6, 9, 9, 11, 10, 10, 9, 11, 11, 10, 6, 9, 9, 11, 10, 10, 9, 11, 11, 10, 10, 16, 16, 18, 17, 17, 16, 18, 18, 17, 16, 19, 19, 21, 21, 20, 20, 22, 21, 21, 19
Offset: 0

Views

Author

N. J. A. Sloane, Apr 20 2023

Keywords

Crossrefs

Cf. A005589.

Programs

  • Python
    from num2words import num2words
    def a(n): return sum(1 for c in num2words(n, lang='en_GB') if c.isalpha())
    print([a(n) for n in range(121)]) # Michael S. Branicky, Apr 21 2023

Extensions

More than the usual number of terms are shown in the DATA field to avoid confusion with A005589.

A030644 Decimal expansion of 10 - Pi.

Original entry on oeis.org

6, 8, 5, 8, 4, 0, 7, 3, 4, 6, 4, 1, 0, 2, 0, 6, 7, 6, 1, 5, 3, 7, 3, 5, 6, 6, 1, 6, 7, 2, 0, 4, 9, 7, 1, 1, 5, 8, 0, 2, 8, 3, 0, 6, 0, 0, 6, 2, 4, 8, 9, 4, 1, 7, 9, 0, 2, 5, 0, 5, 5, 4, 0, 7, 6, 9, 2, 1, 8, 3, 5, 9, 3, 7, 1, 3, 7, 9, 1, 0, 0, 1, 3, 7, 1, 9, 6, 5, 1, 7, 4, 6, 5, 7, 8, 8, 2, 9, 3, 2, 0, 1, 7, 8, 5
Offset: 1

Views

Author

Keywords

Examples

			6.85840734...
		

References

  • Problems Drive, Eureka, 37 (1974), 8-11 and 33.

Crossrefs

Cf. A000796.

Programs

Extensions

More terms from Erich Friedman

A052384 Number of letters in the n-th decimal digit of Pi (in English).

Original entry on oeis.org

3, 4, 3, 4, 4, 3, 3, 4, 5, 4, 5, 4, 5, 4, 5, 3, 5, 5, 4, 3, 3, 3, 4, 5, 5, 5, 5, 3, 5, 4, 4, 4, 3, 5, 5, 4, 3, 4, 5, 3, 3, 4, 5, 4, 4, 5, 5, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 4, 4, 4, 4, 4, 3, 5, 4, 5, 5, 3, 3, 4, 4, 3, 3, 5, 3, 3, 4, 5, 4, 4, 5, 3, 3, 5, 4, 5, 4, 5, 3, 4, 5, 4, 3, 3, 3, 5, 4, 3, 5, 4, 5, 3, 3, 4, 5
Offset: 2

Views

Author

Olivier Herz (olivier.herz(AT)mines.org), Mar 10 2000

Keywords

Crossrefs

Cf. A005589.

Programs

Formula

a(n) = A005589(A000796(n)). - R. J. Mathar, Jun 30 2020
a(n) = A107488(n). - R. J. Mathar, Jun 30 2020

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Oct 02 2000
Offset set to 2. - R. J. Mathar, Jun 30 2020
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