Number of nonisomorphic semigroups of order <= n.

A118581

Number of nonisomorphic semigroups of order <= n.

Terms

    a(0) =1a(1) =2a(2) =7a(3) =31a(4) =219a(5) =2134a(6) =30768a(7) =1658440a(8) =3685688857

External references