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.

Previous Showing 21-28 of 28 results.

A134219 Positions of 19 after decimal point in decimal expansion of Pi.

Original entry on oeis.org

37, 168, 198, 246, 390, 417, 432, 495, 541, 704, 717, 843, 945, 975, 985, 997, 1047, 1166, 1227, 1237, 1345, 1384, 1427, 1535, 1618, 1641, 1733, 1881, 1915, 1944, 2054, 2128, 2821, 2856, 2872, 2897, 2902, 2905, 2918, 2944, 2960, 2997, 3030, 3166, 3337, 3358
Offset: 1

Views

Author

Artur Jasinski, Oct 14 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Transpose[SequencePosition[RealDigits[Pi,10,10000][[1]],{1,9}]][[1]]-1 (* The program uses the SequencePosition function from Mathematica version 10 *) (* Harvey P. Dale, May 09 2016 *)

A014974 Differences between successive locations of zeros in decimal expansion of Pi.

Original entry on oeis.org

18, 4, 11, 6, 6, 8, 12, 9, 10, 5, 7, 4, 14, 13, 5, 3, 9, 19, 12, 38, 3, 16, 6, 17, 4, 16, 1, 3, 16, 3, 10, 17, 3, 1, 5, 3, 6, 23, 5, 5, 13, 22, 8, 42, 20, 7, 3, 20, 2, 7, 5, 4, 35, 5, 1, 1, 15, 20, 19, 2, 10, 13, 2, 19, 12, 5
Offset: 1

Views

Author

Bagirath R. Krishnamachari (bagi(AT)callisto.miel.mot.com)

Keywords

Comments

Assuming Pi is normal, this sequence includes every finite sequence of positive integers. - Franklin T. Adams-Watters, Mar 15 2006

Examples

			First two 0's are in 33rd and 51st digits, difference is 18.
		

Crossrefs

Programs

  • Mathematica
    Differences[Flatten[Position[RealDigits[Pi,10,1000][[1]],0]]] (* Harvey P. Dale, Jul 04 2017 *)

Formula

a(n) = A014976(n+1) - A014976(n). - Michel Marcus, Oct 06 2013

Extensions

More terms from Simon Plouffe.

A133268 a(n) = positions of 0's after decimal point in decimal expansion of 1/Pi.

Original entry on oeis.org

5, 15, 31, 37, 48, 79, 81, 84, 89, 95, 118, 137, 189, 222, 232, 240, 258, 264, 269, 279, 298, 314, 315, 362, 371, 394, 435, 451, 460, 463, 466, 472, 480, 497, 507, 510, 520, 521, 525, 541, 565, 569, 571, 596, 600, 606, 609, 610, 636, 670, 702, 703, 706, 707
Offset: 1

Views

Author

Artur Jasinski, Oct 16 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Flatten[Position[RealDigits[1/Pi,10,1000][[1]],0]] (* Harvey P. Dale, May 16 2012 *)

A134210 Positions of 10 after the decimal point in the decimal expansion of Pi.

Original entry on oeis.org

49, 163, 175, 206, 269, 442, 681, 780, 852, 854, 1011, 1219, 1223, 1270, 1318, 1487, 1816, 1892, 2162, 2238, 2514, 2534, 2563, 2721, 2749, 2780, 2810, 2874, 2880, 2955, 3170, 3201, 3208, 3241, 3254, 3405, 3457, 3480, 3486, 3494, 3845, 3848, 3939, 3964, 3966
Offset: 1

Views

Author

Artur Jasinski, Oct 14 2007

Keywords

Crossrefs

Programs

  • Mathematica
    SequencePosition[RealDigits[Pi,10,10000][[1]],{1,0}][[All,1]]-1 (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 20 2016 *)

Extensions

More terms from Harvey P. Dale, Nov 20 2016

A256521 Table T(n, k) of positions p[i] where number n occurs after the decimal point in the decimal expansion of Pi, read by antidiagonals.

Original entry on oeis.org

32, 50, 1, 54, 3, 6, 65, 37, 16, 9, 71, 40, 21, 15, 2, 77, 49, 28, 17, 19, 4, 85, 68, 33, 24, 23, 8, 7, 97, 94, 53, 25, 36, 10, 20, 13, 106, 95, 63, 27, 57, 31, 22, 29, 11, 116, 103, 73, 43, 59, 48, 41, 39, 18, 5, 121, 110, 76, 46, 60, 51, 69, 47, 26, 12, 49, 128, 138, 83, 64, 70, 61, 72, 56, 34, 14, 163, 94
Offset: 0

Views

Author

Felix Fröhlich, Apr 01 2015

Keywords

Comments

Table T(n, k) starts:
n = 0: 32, 50, 54, 65, 71, 77, 85, 97, 106, 116, ...
n = 1: 1, 3, 37, 40, 49, 68, 94, 95, 103, 110, ...
n = 2: 6, 16, 21, 28, 33, 53, 63, 73, 76, 83, ...
n = 3: 9, 15, 17, 24, 25, 27, 43, 46, 64, 86, ...
n = 4: 2, 19, 23, 36, 57, 59, 60, 70, 87, 92, ...
n = 5: 4, 8, 10, 31, 48, 51, 61, 90, 109, 130, ...
n = 6: 7, 20, 22, 41, 69, 72, 75, 82, 98, 108, ...
n = 7: 13, 29, 39, 47, 56, 66, 96, 99, 120, 139, ...
n = 8: 11, 18, 26, 34, 35, 52, 67, 74, 78, 81, ...
n = 9: 5, 12, 14, 30, 38, 42, 44, 45, 55, 58, ...
n = 10: 49, 163, 175, 206, 269, 442, 681, 780, 852, 854, ...
...

Examples

			T(6, 4) = 41, since the fourth occurrence of 6 in the decimal expansion of Pi is at position 41.
		

Crossrefs

Cf. A000796 (Pi), A014777 (first column).
Cf. A037008, A037000, A037001, A037002, A037003 (0th to 4th row).
Cf. A037004, A037005, A036974, A037006, A037007 (5th to 9th row).

Programs

  • Mathematica
    spi = StringDrop[ ToString[ N[ Pi, 1000]], 2]; t[n_, k_] := StringPosition[ spi, ToString[n], k][[-1, 1]]; Table[ t[n - k, k], {n, 0, 12}, {k, n, 1, -1}] // Flatten (* Robert G. Wilson v, Apr 07 2015 *)

Extensions

More terms from Robert G. Wilson v, Apr 07 2015

A332084 Triangle read by rows: T(n,k) is the smallest m >= 0 such that floor(Pi*n^m) == k (mod n), -1 if one does not exist, k = 0..n-1.

Original entry on oeis.org

0, 1, 0, 0, 2, 4, 1, 3, 2, 0, 1, 7, 3, 0, 8, 1, 9, 14, 0, 10, 2, 1, 7, 10, 0, 8, 6, 2, 3, 1, 8, 0, 9, 6, 14, 5, 10, 1, 2, 0, 3, 20, 18, 11, 5, 32, 1, 6, 0, 2, 4, 7, 13, 11, 5, 5, 1, 8, 0, 13, 4, 2, 6, 9, 24, 12, 5, 1, 22, 0, 3, 17, 14, 18, 2, 6, 20, 10, 5, 1, 10, 0, 6, 9, 17, 14, 23, 7, 2, 21, 3
Offset: 1

Views

Author

Davis Smith, Aug 22 2020

Keywords

Comments

Pi is normal in base n >= 2 if and only if in every row N, such that N is a power of n, -1 does not appear. Pi is absolutely normal if and only if -1 never appears.
Conjecture: Pi is absolutely normal, meaning that -1 will never appear.
This triangle is an instance of the more general f(n,k,r), where f(n,k,r) is the smallest m >= 0 such that floor(r*n^m) == k (mod n) (-1 if one does not exist) and r is irrational. The same conditions for normalcy apply.

Examples

			The triangle T(n,k) starts:
n\k   0   1   2   3   4   5   6   7   8   9  10  11  12 ...
1:    0
2:    1   0
3:    0   2   4
4:    1   3   2   0
5:    1   7   3   0   8
6:    1   9  14   0  10   2
7:    1   7  10   0   8   6   2
8:    3   1   8   0   9   6  14   5
9:   10   1   2   0   3  20  18  11   5
10:  32   1   6   0   2   4   7  13  11   5
11:   5   1  22   0  13   4   2   6   9  24  12
12:   5   1  10   0   3  17  14  18   2   6  20  10
13:   5   1  10   0   6   9  17  14  23   7   2  21   3
		

Crossrefs

Positions of 0 through 9 in base 10: A037000, A037001, A037002, A037003, A037004, A037005, A036974, A037006, A037007, A037008.

Programs

  • PARI
    A332084_row(n)={my(L=List(vector(n,z,-1)), m=-1); while(vecmin(Vec(L))==-1, my(Z=lift(Mod(floor(Pi*n^(m++)),n))+1); if(L[Z]<0,listput(L,m,Z))); Vec(L)}

Formula

T(n,3) = 0, n > 3.

A383732 a(n) is the smallest k such that every digit from 0 to 9 appears at least n times among the first k digits of Pi (after the decimal point).

Original entry on oeis.org

32, 50, 54, 65, 71, 77, 96, 99, 120, 139, 156, 166, 209, 224, 232, 235, 242, 288, 299, 301, 306, 320, 343, 351, 405, 407, 412, 429, 439, 452, 458, 463, 468, 475, 478, 486, 506, 538, 540, 544, 548, 556, 559, 560, 567, 569, 575, 577, 584, 591, 609, 621, 622, 625, 626, 631, 633, 634, 641
Offset: 1

Views

Author

Guy Amit, May 07 2025

Keywords

Comments

The first 6 terms also appear in A037008, the position of the digit 0 in the decimal expansion of Pi.
From Pontus von Brömssen, May 13 2025: (Start)
If the digit "3" before the decimal point is included (but a(n) still represents the number of digits after the decimal point), the first difference to this sequence (i.e., the first time the extra "3" is useful) would be a(229) = 2583 instead of 2597.
For d = 0, 1, ..., 9, the smallest n >= 1 for which d is the last digit to occur n times is 1, 146359, 2100, 229, 94, 61, 118, 7, 794, 9734, respectively.
(End)

Examples

			For n = 1, a(1) = 32 since this is the first position in the decimal expansion of Pi such that every digit from 0 to 9 has appeared at least once among the first 32 digits.
For n = 2, a(2) = 50 since this is the first position in the decimal expansion of Pi such that every digit from 0 to 9 has appeared at least twice among the first 50 digits.
		

Crossrefs

Programs

  • MATLAB
    % Assuming x contains the digits of Pi, x = [1, 4, 1, 5, 9, ...]
    a = nan(1);
    counts = zeros(10, 1);
    n = 1;
    for i = 1:length(x)
        for j = 1:10
            if x(i) == (j-1)
                counts(j) = counts(j) + 1;
            end
        end
        if sum(counts>=n) == 10
            a(n) = i;
            n = n + 1;
        end
    end
  • Mathematica
    piDigit = Rest[RealDigits[Pi, 10, 700][[1]]];
    f[pd_List]:=Module[{res,len,count,n=1},count=CreateDataStructure["FixedArray",ConstantArray[0,10]];res=CreateDataStructure["Queue"];len=Length[pd]; Do[Do[If[pd[[i]]==j-1,count["SetPart",j,1+count["Part",j]]],{j,10}];If[Total[Boole[#>=n]&/@(count["Elements"])]==10,res["Push",i];n++],{i,len}];res["Elements"]];f[piDigit] (* Shenghui Yang, May 19 2025 *) (* or *)
    upto[nd_] := Block[{pi=Rest@ RealDigits[Pi,10,nd][[1]], cnt=0 Range[10], n=1}, Reap[Do[cnt[[pi[[j]] + 1]]++; If[Min[cnt-n] == 0, n++; Sow@j], {j, Length@ pi}]][[2,1]]]; upto[700] (* for older Mma, Giovanni Resta, May 22 2025 *)

A101196 Position of n-th n after the decimal point in Pi.

Original entry on oeis.org

1, 16, 17, 36, 48, 72, 96, 74, 55, 854, 709, 1080, 1076, 1636, 1657, 1651, 889, 1674, 1227, 2039, 1486, 2372, 2690, 2288, 2033, 2282, 1785, 2703, 4155, 3102, 3584, 3767, 4325, 3808, 3551, 4081, 3785, 3229, 4464, 4884, 4127, 4228, 5336, 3961, 4242, 3633
Offset: 1

Views

Author

Michael Joseph Halm, Dec 12 2004

Keywords

Examples

			a(2) = 16 because the second occurrence of 2 in the digits of pi after its decimal point is at position 16, that is, after 141592653589793.
		

Crossrefs

Extensions

Corrected and extended by Mark Hudson (mrmarkhudson(AT)hotmail.com), Dec 13 2004
Previous Showing 21-28 of 28 results.