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 A019272 #2 Dec 11 1999 03:00:00 %S A019272 1,14,33,242,11605,28374,171893 %N A019272 Erroneous version of A006558. %K A019272 dead %O A019272 1,2