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 A067387 #4 Feb 27 2009 03:00:00 %S A067387 3,5,17,257,65537,641,6700417,274177,67280421310721,59649589127497217 %N A067387 Duplicate of A050922. %K A067387 dead %O A067387 1,1