Number of commutative semigroups of order <= n.

A118100

Number of commutative semigroups of order <= n.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =17a(4) =75a(5) =400a(6) =2543a(7) =19834a(8) =241639a(9) =11787482a(10) =3530717819

External references