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 A058120 #6 Mar 30 2012 17:37:11 %S A058120 1,5,24,123,754,6721 %N A058120 Number of self-converse semigroups of order n with 2 idempotents. %H A058120 <a href="/index/Se#semigroups">Index entries for sequences related to semigroups</a> %Y A058120 Column 2 of A058118. %K A058120 nonn,hard %O A058120 2,2 %A A058120 _Christian G. Bower_, Nov 10 2000