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 A084180 #4 Sep 29 2006 03:00:00 %S A084180 0,2,10,42,170,682,2730,10922,43690,174762,699050,2796202,11184810 %N A084180 Duplicate of A020988. %K A084180 dead %O A084180 0,2