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 A058168 #6 Mar 30 2012 17:37:12 %S A058168 1,2,1,3,5,1,7,18,12,2,24,65,73,34,5,133,276,399,309,123,18,1722,1595, %T A058168 2240,2331,1500,544,81 %N A058168 Triangle: Number of asymmetric commutative semigroups of order n with k idempotents. %H A058168 <a href="/index/Se#semigroups">Index entries for sequences related to semigroups</a> %e A058168 1; 2,1; 3,5,1; 7,18,12,2; 24,65,73,34,5; ... %Y A058168 Row sums give A058105. %K A058168 nonn,tabl,hard %O A058168 1,2 %A A058168 _Christian G. Bower_, Nov 19 2000