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 A007881 #3 Dec 11 1999 03:00:00 %S A007881 1,2,4,8,18,71 %N A007881 Erroneous version of A001357 printed by mistake on back cover of Encyclopedia of Integer Sequences. %K A007881 dead %O A007881 0,2