Triangle: self-converse semigroups of order n with k idempotents.

Terms

a(0) =1a(1) =2a(2) =1a(3) =5a(4) =5a(5) =2a(6) =18a(7) =24a(8) =16a(9) =6a(10) =93a(11) =123a(12) =112a(13) =58a(14) =19a(15) =930a(16) =754a(17) =764a(18) =542a(19) =254a(20) =68a(21) =22899a(22) =6721a(23) =5567a(24) =4751a(25) =2933a(26) =1214a(27) =285a(28) =1937266a(29) =123988