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 A033108 #7 Nov 15 2012 04:27:34
%S A033108 0,0,0,0,0,0,1,1,1,1,1,1,1,1,2,3,4,5,6,7,8,9,11,12,14,15,17,18,20,21,
%T A033108 24,25,27,29,31,32,35,36,39,41,43,44,48,49,51,53,57,58,61,62,65,68,70,
%U A033108 71,76,78,82,85,89,91,96,99,105,108,111,113,120
%N A033108 Number of 7's when k is written in base b for all b and k satisfying 2<=b<=n+1, 1<=k<=n.
%t A033108 f[n_] := Count[ Flatten@ Table[ IntegerDigits[k, b], {k, n}, {b, 2, n + 1}], 7] - (n - 7); f[1] = f[2] = f[3] = f[4] = f[5] = f[6] = 0; Array[f, 67] (* _Robert G. Wilson v_, Nov 14 2012 *)
%Y A033108 Cf. A033094, A033096, A033098, A033100, A033102, A033104, A033106, A033107, A033110, A033112.
%K A033108 nonn,base
%O A033108 1,15
%A A033108 _Clark Kimberling_