Number of labeled directed multigraphs with n arcs for which every vertex has in-degree at least one and out-degree at least one.

A121063

Number of labeled directed multigraphs with n arcs for which every vertex has in-degree at least one and out-degree at least one.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =4a(4) =27a(5) =246a(6) =2783a(7) =37424a(8) =582153a(9) =10276452a(10) =202894801a(11) =4429522252a(12) =105943672079

External references