Number of endofunctions on [n] such that no element has a preimage of cardinality four.

A245408

Number of endofunctions on [n] such that no element has a preimage of cardinality four.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =27a(4) =252a(5) =3025a(6) =44406a(7) =770623a(8) =15434616a(9) =350420337a(10) =8893045900a(11) =249474767861

External references