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 A133249 #3 Mar 30 2012 17:34:22
%S A133249 7,14,20,21,25,30,31,33,37,38,39,40,41,42,45,47,48,49,51,52,53,55,60
%N A133249 Location of ones in the binary representation of Chaitan's Omega: If[A124027(n)==0, then n.
%F A133249 a(n) = If[A124027(m)==0, then (m)
%t A133249 (*A079365*); c = {0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1,1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0,1, 0, 0, 0, 0, 1, 0, 0, 0, 0}; Flatten[Table[If[c[[n]] == 1, n, {}], {n, 1, Length[c]}]]
%Y A133249 Cf. A079365, A124027.
%K A133249 nonn
%O A133249 1,1
%A A133249 _Roger L. Bagula_, Oct 14 2007