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 A045781 #6 May 11 2007 03:00:00 %S A045781 1,2,3,2,3,4,3,4,5,4,5,6,3,4,4,5,4,5,5,6,4,5 %N A045781 Erroneous version of A045670. %K A045781 dead %O A045781 1,2