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 A001493 #9 Jul 31 2010 03:00:00 %S A001493 1,1,1,2,7,8,37,40,200,258,1039,1500 %N A001493 Erroneous version of A000637. %K A001493 dead %O A001493 0,4