A097614 In the decimal expansion of Pi, the string "0" is found at position 32 counting from the first digit after the decimal point. The string "32" is found at position 15, the string "15" at position 3, the string "3" at position 9, etc.

0, 32, 15, 3, 9, 5, 4, 2, 6, 7, 13, 110, 174, 155, 314, 2120, 5360, 24671, 119546, 193002, 240820, 274454, 153700, 1397287, 17916598, 26245242, 8880928, 7320921, 14726415, 42969065, 35308126, 14978764, 68756682, 300921774

Offset: 0

Author

Eric Angelini, Aug 30 2004

Keywords

• nonn
• base

Links

• Dave Andersen, The Pi-Search Page.
• Anders Hellström, Sage program

Crossrefs

Cf. A014777.

Programs

Mathematica

Function[c, NestList[SequencePosition[c, IntegerDigits@ #][[1, 1]] &, 0, 23]]@ Rest@ First@ RealDigits[N[Pi, 10^7]] (* Michael De Vlieger, Jan 23 2017, Version 10.1 *)

PARI

M97614=[]; A097614(n)={while(n > #M97614, M97614=concat(M97614, A014777(A097614(#M97614)))); if(n, M97614[n],0)} \\ M. F. Hasler, Jun 21 2022

Python

def A097614(n):
    while n >= len(A097614.list):
        A097614.list.append(A014777(A097614.list[-1]))
    return A097614.list[n]
A097614.list = [0] # M. F. Hasler, Jun 21 2022

Formula

a(0) = 0, a(1) = A014777(0) = 32, a(n) = A014777(a(n-1)), for n>1. - Anders Hellström, Jan 21 2017

Extensions

a(33) from Michael S. Branicky, Dec 05 2024