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 A088923 #3 May 11 2007 03:00:00 %S A088923 9,19,29,39,49,59,69,79,89,90,91,92,93,94,95,96,97,98,99,109,119,129 %N A088923 Duplicate of A011539. %K A088923 dead %O A088923 1,1