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 A033098 #8 Nov 15 2012 04:26:10
%S A033098 0,1,1,1,2,4,6,10,12,16,20,24,27,34,38,44,51,58,63,72,77,86,94,103,
%T A033098 111,125,132,139,147,156,162,175,183,195,207,217,228,244,253,264,276,
%U A033098 292,303,319,329,343,358,370,381,401,415,432,448
%N A033098 Number of 2's when k is written in base b for all b and k satisfying 2<=b<=n+1, 1<=k<=n.
%t A033098 f[n_] := Count[ Flatten@ Table[ IntegerDigits[k, b], {k, n}, {b, 2, n + 1}], 2] - (n - 2); Array[f, 53] (* _Robert G. Wilson v_, Nov 14 2012 *)
%Y A033098 Cf. A033094, A033096, A033097, A033100, A033102, A033104, A033106, A033108, A033110, A033112.
%K A033098 nonn,base
%O A033098 1,5
%A A033098 _Clark Kimberling_