Number of labeled directed multigraphs with n arrows and no vertex of degree 0.

A104209

Number of labeled directed multigraphs with n arrows and no vertex of degree 0.

Terms

    a(0) =1a(1) =3a(2) =39a(3) =819a(4) =23949a(5) =898947a(6) =41212155a(7) =2232057171a(8) =139455901101

External references