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 A075725 #4 May 11 2007 03:00:00 %S A075725 1,2,3,5,6,8,9,12,15,17,18,21,29,30,32,39,41,42,44,48,53,54,56,60,69 %N A075725 Duplicate of A049407. %K A075725 dead %O A075725 1,2