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

Terms

a(0) =1a(1) =2a(2) =1a(3) =3a(4) =5a(5) =1a(6) =9a(7) =19a(8) =14a(9) =2a(10) =52a(11) =82a(12) =88a(13) =43a(14) =6a(15) =624a(16) =470a(17) =556a(18) =410a(19) =162a(20) =24a(21) =19027a(22) =4444a(23) =3771a(24) =3501a(25) =2088a(26) =731a(27) =110