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 A058122 #6 Mar 30 2012 17:37:11 %S A058122 1,1,1,2,6,19,68,285 %N A058122 Number of self-converse idempotent semigroups of order n. %H A058122 <a href="/index/Se#semigroups">Index entries for sequences related to semigroups</a> %Y A058122 Main diagonal of A058118. %K A058122 nonn,hard %O A058122 0,4 %A A058122 _Christian G. Bower_, Nov 10 2000