Number of asymmetric semigroups of order n.

A058104

Number of asymmetric semigroups of order n.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =15a(4) =112a(5) =1221a(6) =19684a(7) =1458882a(8) =3667253972

External references