Number of unlabeled antichains of finite sets spanning n vertices without singletons.

A304998

Number of unlabeled antichains of finite sets spanning n vertices without singletons.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =3a(4) =15a(5) =160a(6) =15963a(7) =489980652

External references