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 A058113 #6 Mar 30 2012 17:37:11 %S A058113 1,2,1,3,9,3,11,37,52,12,112,224,434,383,68,4398,1984,3976,5568,3256, %T A058113 502,1181185,47622,44581,74851,74604,31881,4158 %N A058113 Triangle: Number of asymmetric semigroups of order n with k idempotents. %H A058113 <a href="/index/Se#semigroups">Index entries for sequences related to semigroups</a> %e A058113 1; 2,1; 3,9,3; 11,37,52,12; 112,224,434,383,68; ... %Y A058113 Row sums give A058104. Main diagonal: A058115. Column 1: A058114. %K A058113 nonn,tabl,hard %O A058113 1,2 %A A058113 _Christian G. Bower_, Nov 09 2000 %E A058113 Updated Feb 19 2001