A063591 - OEIS

A063591

Smallest k such that 5^k has exactly n 6's in its decimal representation.

%I #6 Jun 26 2018 19:16:26

%S 1,4,10,18,38,32,49,51,86,84,83,105,144,138,103,160,146,170,206,229,

%T 180,198,225,227,237,292,256,302,326,324,260,316,352,362,388,419,448,

%U 386,431,497,494,414,416,490,482,473,508,562,547,582,469

%N Smallest k such that 5^k has exactly n 6's in its decimal representation.

%t a = {}; Do[k = 1; While[ Count[ IntegerDigits[5^k], 6] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

%K base,nonn

%O 0,2

%A _Robert G. Wilson v_, Aug 10 2001

%E Name corrected by _Jon E. Schoenfield_, Jun 26 2018