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 A086413 #2 Jan 09 2009 03:00:00 %S A086413 0,1,1,2,2,3,2,3,4,3,4,3,5,4,5,4,6,5,4,6,5,7,6,5,7,6,5,8,7,6,8,7,6,9,8 %N A086413 Duplicate of A069352. %K A086413 dead %O A086413 1,4