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 A047757 #3 Feb 27 2009 03:00:00 %S A047757 0,0,1,5,26,133,708,3861,21604,123266,715221,4206956,25032840, %T A047757 150413348 %N A047757 Duplicate of A047755. %K A047757 dead %O A047757 0,4