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 A078749 #4 May 11 2007 03:00:00 %S A078749 2,3,7,13,42,55,2841 %N A078749 Duplicate of A051130. %K A078749 dead %O A078749 1,1