Number of connected 2n-regular loopless multigraphs on 2n unlabeled nodes.

A289986

Number of connected 2n-regular loopless multigraphs on 2n unlabeled nodes.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =120a(4) =543116a(5) =635669057538

External references