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 A091312 #5 Jun 29 2008 03:00:00 %S A091312 2,7,31,211,2311,200560490131 %N A091312 Erroneous version of A018239. %K A091312 dead %O A091312 1,1