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 A039659 #1 Dec 11 1999 03:00:00 %S A039659 0,1,5,21,50,355 %N A039659 Erroneous version of A039919. %K A039659 dead %O A039659 1,3