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 A077278 #4 May 11 2007 03:00:00 %S A077278 2,5,13,31,43,67,79,97,131,179,199,257,293,313,359,389,409,431,443,467 %N A077278 Duplicate of A073683. %K A077278 dead %O A077278 1,1