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 A126208 #5 Aug 24 2012 10:49:58 %S A126208 0,1,1,1,1,1,3,1,3,2,4,2,2,3,3,1,1,4,4,2,4,3,3,2,3,1,1,3,3,4,1,3,4,7, %T A126208 3,2,2,4,6,4,4,3,3,3,2,5,6,1,2,5,8,7,6,4,3,6,5,5,9,6,7,7,7,5,13,8,4,5, %U A126208 5,2,7,4,6,5,5,12,11,4,10,7,5,11,14,9,9,9,9,7,8,10,6,8,9,6,6,7,12,9,12,11 %N A126208 Number of 6's in decimal expansion of 6^n. %p A126208 P:=proc(n) local i,k,x,y,w,cont; y:=6; k:=y; for i from 0 by 1 to n do x:=y^i; cont:=0; while x>0 do w:=x-trunc(x/10)*10; if w=k then cont:=cont+1; fi; x:=trunc(x/10); od; print(cont); od; end: P(100); %Y A126208 Cf. A065710, A126205, A126206, A126207, A126209, A126210, A126211. %K A126208 nonn,base %O A126208 0,7 %A A126208 _Paolo P. Lava_ and _Giorgio Balzarotti_, Dec 20 2006