

A193940


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


2



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

0,2


COMMENTS

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



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[Pi3, 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



KEYWORD

nonn,base,hard,more


AUTHOR



EXTENSIONS



STATUS

approved



