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 A126727 #3 Mar 30 2012 16:50:37 %S A126727 13,15,19,20,21,23,26,29,30,32,35,37,38,40,42,44,45,46,50,51,52,53,55, %T A126727 56,58,59,60,61,63,64,66,67,68,69,70,74,75,76,77,79,80,81,83,84,85,87, %U A126727 88,89,90,92,93,95,96,99,100,101,102,104,106,109,110,112,113,115,116,117,118 %N A126727 Numbers missing from A033491. %K A126727 nonn %O A126727 1,1 %A A126727 _N. J. A. Sloane_, Feb 16 2007