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 A045640 #4 May 11 2007 03:00:00 %S A045640 5,55,505,515,525,535,545,555,565,575,585,595,5005,5115,5225 %N A045640 Duplicate of A043040. %K A045640 dead %O A045640 1,1