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 A063568 #10 Aug 05 2019 11:52:24
%S A063568 8,3,2,5,11,1,4,7,7,8,14,23,3,30,12,6,20,15,22,9,13,33,13,22,12,2,18,
%T A063568 37,11,17,15,5,19,35,19,14,20,21,18,8,12,12,37,20,12,17,18,21,11,26,
%U A063568 23,14,16,9,30,23,6,15,16,24,24
%N A063568 5^a(n) is the smallest positive power of 5 having n in its decimal representation.
%H A063568 Harvey P. Dale, <a href="/A063568/b063568.txt">Table of n, a(n) for n = 0..1000</a>
%t A063568 a = {}; Do[k = 1; While[ StringPosition[ ToString[5^k], ToString[n]] == {}, k++ ]; a = Append[a, k], {n, 0, 60} ]; a
%t A063568 sp5[n_]:=Module[{k=1,idn=IntegerDigits[n]},While[SequenceCount[ IntegerDigits[ 5^k], idn] == 0,k++];k]; Array[sp5,70,0] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Aug 05 2019 *)
%Y A063568 Essentially the same as A062522.
%K A063568 base,nonn
%O A063568 0,1
%A A063568 _Robert G. Wilson v_, Aug 10 2001