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

A245407

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

Terms

    a(0) =1a(1) =1a(2) =4a(3) =24a(4) =208a(5) =2325a(6) =31956a(7) =520723a(8) =9812160a(9) =209843145a(10) =5020469200a(11) =132844628411

External references