This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A062524 #5 Oct 03 2014 02:31:22
%S A062524 4,0,4,3,2,7,5,1,5,2,13,6,12,12,19,15,5,6,19,11,12,22,14,7,4,30,11,23,
%T A062524 10,16,14,19,11,16,3,7,9,19,12,17,4,12,27,3,18,21,32,10,8,2,15,17,10,
%U A062524 9,7,21,15,8,21,18,9,15,18,17,6,27,20,11,5,16,33,27,12,11,11,10
%N A062524 7^a(n) is smallest nonnegative power of 7 containing the string 'n'.
%C A062524 See A176767 for the actual powers 7^a(n). - _M. F. Hasler_, Oct 03 2014
%t A062524 Table[k = 0; While[ StringPosition[ ToString[7^k], ToString[n] ] == {}, k++ ]; k, {n, 0, 75} ]
%Y A062524 Cf. A030000.
%Y A062524 Essentially the same as A063570.
%K A062524 base,nonn
%O A062524 0,1
%A A062524 _Robert G. Wilson v_, Jun 24 2001