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.

Showing 1-10 of 13 results. Next

A049523 Smallest starting index for a run of exactly n consecutive equal digits in decimal expansion of Pi.

Original entry on oeis.org

1, 25, 154, 1590, 17535, 763, 710101, 22931746, 24658602, 386980413, 15647738229, 368299898267, 2164164669333, 5758910552710, 46970519777308
Offset: 1

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Author

Keywords

Comments

Digits 3,1,4,1,5,... are indexed 1,2,3,4,5,...
a(11) > 2*10^9. - M. F. Hasler, Mar 22 2017
a(12) > 99*10^9. - Giovanni Resta, Oct 02 2019
a(15) > 12*10^12. - Dmitry Petukhov, Dec 30 2019
a(16) > 50*10^12, a(17) = 28642224609576. - Dmitry Petukhov, Oct 30 2021

Examples

			See A084144 for an example.
		

Crossrefs

Cf. A084144 (digit with this starting index).

Extensions

More terms from Rick L. Shepherd, May 15 2003
Edited and a(10) (via Taylor's search engine) added by M. F. Hasler, Mar 21 2017
a(11) from Giovanni Resta, Oct 02 2019
a(12)-a(14) added by Dmitry Petukhov, Dec 30 2019
a(15) from Dmitry Petukhov, Oct 30 2021

A049522 Smallest starting index for a run of at least n consecutive equal digits in decimal expansion of Pi.

Original entry on oeis.org

1, 25, 154, 763, 763, 763, 710101, 22931746, 24658602, 386980413, 15647738229, 368299898267, 2164164669333, 5758910552710, 28642224609577, 28642224609577, 28642224609577
Offset: 1

Views

Author

Keywords

Comments

Digits 3,1,4,1,5,... are indexed 1,2,3,4,5,...
a(11) > 2*10^9. - M. F. Hasler, Mar 21 2017
a(12) > 99*10^9. - Giovanni Resta, Oct 02 2019
a(15) > 12*10^12. - Dmitry Petukhov, Dec 30 2019
a(18) > 50*10^12. - Dmitry Petukhov, Oct 30 2021

Crossrefs

Compare A049523: the first run of six 9's occurs (with starting index 763) before any runs of exactly four or exactly five equal digits.
Cf. A084145 (digit with this starting index).

Extensions

More terms from Rick L. Shepherd, May 22 2003
a(10) from Felix Fröhlich, Oct 06 2016
a(11) from Giovanni Resta, Oct 02 2019
a(12)-a(14) added by Dmitry Petukhov, Dec 30 2019
a(15)-a(17) from Dmitry Petukhov, Oct 30 2021
a(15)-a(17) had off-by-1 error, corrected by Mike Keith, Feb 03 2025

A049518 Starting index of a string of exactly 2 consecutive equal digits in the decimal expansion of Pi.

Original entry on oeis.org

25, 35, 45, 60, 80, 95, 118, 126, 131, 136, 175, 183, 186, 202, 205, 212, 216, 218, 231, 258, 277, 283, 308, 310, 316, 318, 323, 361, 363, 365, 373, 378, 396, 402, 428, 438, 446, 454, 460, 473, 485, 495, 504, 508, 512, 517, 536, 560, 593, 622
Offset: 0

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Author

Keywords

Comments

Digits 3,1,4,... are indexed 1,2,3,...
See A049514 for the variant "at least 2", which differs from a(11) on. - M. F. Hasler, Oct 18 2019

Examples

			From _M. F. Hasler_, Oct 18 2019: (Start)
The integer part of Pi*10^22 ends in 33, i.e., at position 22 starts the (first) string of two repeated digits 3, therefore a(1) = 22.
At position 154 starts a string of three '1's, so sequence A049514 lists both, 154 and 155, but this sequence lists none of these. (End)
		

Crossrefs

Programs

A049519 Starting index of a string of exactly 3 consecutive equal digits in decimal expansion of Pi.

Original entry on oeis.org

154, 178, 602, 856, 984, 1233, 1451, 1599, 1699, 1736, 1890, 2279, 2360, 2377, 2441, 2675, 2708, 2929, 2950, 3152, 3435, 3477, 3504, 3810, 3867, 3993, 4001, 4176, 4256, 4436, 4509, 4576, 4794, 4924, 4929, 4986, 5291, 5356, 5404, 5451, 5676, 5872, 6071
Offset: 0

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Author

Keywords

Comments

Digits 3,1,4,... are indexed 1,2,3,...

Crossrefs

Programs

  • Mathematica
    e3cdQ[{a_,b_,c_,d_,e_}]:=a!=b&&d!=e&&b==c==d; Flatten[Position[ Partition[ RealDigits[Pi,10,7000][[1]],5,1],?(e3cdQ)]]+1 (* _Harvey P. Dale, Nov 09 2016 *)

A049521 Starting index of a string of exactly 5 consecutive equal digits in decimal expansion of Pi.

Original entry on oeis.org

17535, 19447, 24467, 28468, 32789, 39862, 48440, 56989, 65261, 89086, 102388, 120460, 140745, 141900, 146044, 161863, 162249, 205035, 205194, 211059, 213246, 215288, 220569, 250130, 266895, 283694, 309380, 322348, 327075, 335793, 363996
Offset: 0

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Author

Keywords

Comments

Digits 3,1,4,... are indexed 1,2,3,...

Crossrefs

A049515 Starting index of a string of 3 or more consecutive equal digits in decimal expansion of Pi.

Original entry on oeis.org

154, 178, 602, 763, 764, 765, 766, 856, 984, 1233, 1451, 1590, 1591, 1599, 1699, 1736, 1890, 2279, 2360, 2377, 2441, 2675, 2708, 2929, 2950, 3152, 3435, 3477, 3504, 3810, 3867, 3993, 4001, 4176, 4256, 4436, 4509, 4576, 4752, 4753, 4794, 4903, 4904, 4924
Offset: 1

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Author

Keywords

Comments

Digits 3,1,4,... are indexed 1,2,3,...

Crossrefs

Programs

  • Mathematica
    ConsecutiveOccurrences1[alist_, n_] := Flatten @ Position[ Apply[ SameQ, Partition[ alist, n, 1], {1}], True]; ConsecutiveOccurrences1[ First[ RealDigits[Pi, 10, 4928]], 3]
    SequencePosition[RealDigits[Pi,10,5000][[1]],{x_,x_,x_}][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 19 2019 *)

Extensions

Edited by Robert G. Wilson v, May 09 2003

A049517 Starting index of a string of 5 or more consecutive equal digits in decimal expansion of Pi.

Original entry on oeis.org

763, 764, 17535, 19447, 24467, 28468, 32789, 39862, 48440, 56989, 65261, 89086, 102388, 120460, 140745, 141900, 146044, 161863, 162249, 193035, 193036, 205035, 205194, 211059, 213246, 215288, 220569, 222300, 222301, 244454, 244455, 250130
Offset: 1

Views

Author

Keywords

Comments

Digits 3,1,4,... are indexed 1,2,3,...

Crossrefs

Programs

  • Mathematica
    ConsecutiveOccurrences1[alist_, n_] := Flatten @ Position[ Apply[ SameQ, Partition[ alist, n, 1], {1}], True]; ConsecutiveOccurrences1[ First[ RealDigits[Pi, 10, 252499]], 5]

Extensions

Edited by Robert G. Wilson v, May 09 2003

A049520 Starting index of a string of exactly 4 consecutive equal digits in decimal expansion of Pi.

Original entry on oeis.org

1590, 4752, 4903, 5242, 5323, 5864, 7965, 12487, 12701, 13391, 16733, 17989, 19438, 21881, 22754, 29505, 29869, 30797, 31901, 32428, 32479, 33108, 33173, 35458, 37231, 37323, 40793, 42096, 43155, 43406, 43524, 46513, 48666, 49056
Offset: 0

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Author

Keywords

Comments

Digits 3,1,4,... are indexed 1,2,3,...

Crossrefs

Programs

A095916 Differences between adjacent digits of Pi.

Original entry on oeis.org

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

Views

Author

Herman Jamke (hermanjamke(AT)fastmail.fm), Jul 13 2004

Keywords

Comments

a(A049514(n)) = 0. - Reinhard Zumkeller, Mar 12 2015

Crossrefs

Programs

  • Haskell
    a095916 n = a095916_list !! (n-1)
    a095916_list = zipWith (-) (tail a000796_list) a000796_list
    -- Reinhard Zumkeller, Mar 12 2015
  • Mathematica
    b = RealDigits[N[Pi, 1000]]; b = First[b]; a = {}; Do[k = b[[n + 1]] - b[[n]]; AppendTo[a, k], {n, 1, 999}]; a (* Artur Jasinski, Mar 16 2008 *)
    Differences[RealDigits[Pi,10,120][[1]]] (* Harvey P. Dale, Feb 10 2013 *)

A049516 Starting index of a string of 4 or more consecutive equal digits in decimal expansion of Pi.

Original entry on oeis.org

763, 764, 765, 1590, 4752, 4903, 5242, 5323, 5864, 7965, 12487, 12701, 13391, 16733, 17535, 17536, 17989, 19438, 19447, 19448, 21881, 22754, 24467, 24468, 28468, 28469, 29505, 29869, 30797, 31901, 32428, 32479, 32789, 32790, 33108
Offset: 1

Views

Author

Keywords

Comments

Digits 3,1,4,... are indexed 1,2,3,...

Crossrefs

Programs

  • Mathematica
    ConsecutiveOccurrences1[alist_, n_] := Flatten @ Position[ Apply[ SameQ, Partition[ alist, n, 1], {1}], True]; ConsecutiveOccurrences1[ First[ RealDigits[Pi, 10, 33172]], 4]
    SequencePosition[RealDigits[Pi,10,34000][[1]],{x_,x_,x_,x_}][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jan 16 2019 *)

Extensions

Edited by Robert G. Wilson v, May 09 2003
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