cp's OEIS Frontend

A259443 The position of the first occurrence in the decimal expansion of Pi of n identical digits.

%I A259443 #21 Aug 23 2015 17:03:48
%S A259443 1,3,10,24,25,27,43,45,55,58,62,79,80,100,107,113,124,134,147,150,152,
%T A259443 161,171,186,197,204,205,222,228,233,236,255,267,273,278,293,296,303,
%U A259443 321,334,337,354,373,380,386,392,400,432,437,438,442,445,446,471,483,490,494,495,499
%N A259443 The position of the first occurrence in the decimal expansion of Pi of n identical digits.
%C A259443 A test for normality.
%H A259443 Robert G. Wilson v, <a href="/A259443/b259443.txt">Table of n, a(n) for n = 1..1000</a>
%F A259443 a(n) ~ 10*n and a(n-1) < a(n).
%F A259443 a(10) = 58, a(100) = 882, a(1000) = 9619, a(10000) = 98564, a(100000) = 996482.
%e A259443 a(2) = 3 since the digit 1 occurs twice by the third place in the decimal expansion of Pi, i.e., "141".
%e A259443 a(3) = 10 since the digit 5 occurs three times by the tenth place in the decimal expansion of Pi, i.e., "1415926535".
%t A259443 pi3 = RealDigits[Pi - 3, 10, 1000][[1]]; f[n_] := f[n] = Block[{k = f[n - 1] + 1}, While[ Max[ Transpose[ Tally[ Take[pi3, k]]][[2]]] != n, k++]; k]; f[0] = 0; Array[f, 60]
%Y A259443 Cf. A000796, A159345.
%K A259443 base,easy,nonn
%O A259443 1,2
%A A259443 _Douglas Boffey_ and _Robert G. Wilson v_, Jun 27 2015