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 A026864 #4 Mar 30 2012 18:56:11 %S A026864 1,11,79,472,2554,13024,63958,306382,1443463,6725059,31101315, %T A026864 143160979,657181579,3012930550,13810302898,63339713546,290848317898, %U A026864 1337717758649,6164619409085,28469921477415,131784947615381,611477036684719 %N A026864 T(2n,n+4), T given by A026747. %K A026864 nonn %O A026864 4,2 %A A026864 _Clark Kimberling_