A193940 Starting position of the first occurrence of the decimal number 10^n in the decimal expansion of Pi.

1, 49, 854, 854, 387791, 2393355, 10359802, 13310435, 172330849, 2542542101, 95257866194, 1587461837108, 3186699229889, 3186699229889

Offset

0,2

Comments

From Dmitry Petukhov, Jan 15 2020: (Start)

Digits 3,1,4,1,5,... are indexed 0,1,2,3,4,...

10^2 without '0' after it found at 1816 position, but a(3)=854 < 1816, therefore a(2)=a(3)=854.

10^12 without '0' after it found at 6029081077667 position, but a(13)=3186699229889 < 6029081077667, therefore a(12)=a(13). (End)

Links

Table of n, a(n) for n=0..13.

Peter Trüb, 22.4 trillion digits of pi

Example

Pi = 3.141592653589793238462643383279502884197169399375105.. The '1' (10^0) after the decimal point is at position 1. The '1' of the first occurrence of '10' (10^1) is at position 49.

Mathematica

str = ToString[N[Pi-3, 2*10^8]]; s = "1"; Table[pos = StringPosition[str, s, 1][[1, 1]] - 2; s = s <> "0"; pos, {9}] (* this code takes a long time. T. D. Noe, Aug 10 2011 *)

Crossrefs

Cf. A000796, A176341, A194351.

Sequence in context: A357653 A278284 A110906 * A012115 A284642 A304046

Adjacent sequences: A193937 A193938 A193939 * A193941 A193942 A193943

Keyword

nonn,base,hard,more

Author

Kausthub Gudipati, Aug 10 2011

Extensions

Edited by Hans Havermann, Jul 21 2014

a(9) from Hans Havermann, Jul 21 2014

a(10)-a(13) from Dmitry Petukhov, Jan 15 2020

Status

approved