Number of nonisomorphic semigroups with n elements satisfying the equation xyz = xy.

A390163

Number of nonisomorphic semigroups with n elements satisfying the equation xyz = xy.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =14a(6) =47a(7) =194a(8) =1153a(9) =10525a(10) =164430a(11) =4731263

External references