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 A058109 #5 Mar 30 2012 17:37:11 %S A058109 1,2,5,20,171,5284,1224331 %N A058109 Semigroups of order n with 1 idempotent. %H A058109 <a href="/index/Se#semigroups">Index entries for sequences related to semigroups</a> %Y A058109 Column 1 of A058108. %K A058109 nonn,hard %O A058109 1,2 %A A058109 _Christian G. Bower_, Nov 09 2000 %E A058109 Updated Feb 19 2001