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 A033101 #8 Nov 14 2012 18:09:10
%S A033101 0,0,0,1,0,0,0,0,1,1,1,1,1,2,1,2,1,2,2,3,2,4,2,5,3,3,2,6,4,3,3,5,3,7,
%T A033101 2,5,4,4,5,7,3,4,4,8,4,8,4,7,8,4,3,9,5,7,4,6,4,8,6,9,6,6,5,13,5,5,7,8,
%U A033101 7,9,5,8,7,11,4,12,6,7,9,8,8,10,6,12,7,6,5,13
%N A033101 Number of 4's when n is written in base b for 2<=b<=n+1.
%t A033101 f[n_] := Count[Flatten@ Table[ IntegerDigits[n, b], {b, 2, n + 1}], 4]; Array[f, 88] (* _Robert G. Wilson v_, Nov 14 2012 *)
%Y A033101 Cf. A033093, A033095, A033097, A033099, A033102, A033103, A033105, A033107, A033109, A033111.
%K A033101 nonn,base
%O A033101 1,14
%A A033101 _Clark Kimberling_