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 A151516 #3 Nov 22 2010 10:09:34 %S A151516 1,1,2,4,10,24,67,182,520,1474,4248,12196 %N A151516 Duplicate of A003104. %K A151516 dead %O A151516 1,3