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 A033097 #8 Nov 14 2012 18:07:38
%S A033097 0,1,0,0,1,2,2,4,2,4,4,4,3,7,4,6,7,7,5,9,5,9,8,9,8,14,7,7,8,9,6,13,8,
%T A033097 12,12,10,11,16,9,11,12,16,11,16,10,14,15,12,11,20,14,17,16,15,12,19,
%U A033097 15,19,16,16,15,25,15,17,19,19,17,21,16,19,18
%N A033097 Number of 2's when n is written in base b for 2<=b<=n+1.
%t A033097 f[n_] := Count[Flatten@ Table[ IntegerDigits[n, b], {b, 2, n + 1}], 2]; Array[f, 70] (* _Robert G. Wilson v_, Nov 14 2012 *)
%Y A033097 Cf. A033093, A033095, A033098, A033099, A033101, A033103, A033105, A033107, A033109, A033111.
%K A033097 nonn,base
%O A033097 1,6
%A A033097 _Clark Kimberling_