Number of block permutations on an n-set.

A023997

Number of block permutations on an n-set.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =25a(4) =339a(5) =6721a(6) =179643a(7) =6166105a(8) =262308819a(9) =13471274401a(10) =818288740923

External references