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 A066533 #2 Sep 13 2003 03:00:00 %S A066533 0,1,3,4,6,7,8,9,10,11,13,14,15 %N A066533 Erroneous version of A058986. %K A066533 dead %O A066533 1,3