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 A078507 #4 Feb 27 2009 03:00:00 %S A078507 0,4,5,9,12,17,21,29,32,39,49,52,58,73,76,88,92,109,117,125,140,151, %T A078507 159 %N A078507 Duplicate of A060199. %K A078507 dead %O A078507 0,2