Consider the family of directed multigraphs enriched by the species of parts. Sequence gives number of those multigraphs with n labeled arcs.

A098631

Consider the family of directed multigraphs enriched by the species of parts. Sequence gives number of those multigraphs with n labeled arcs.

Terms

    a(0) =1a(1) =2a(2) =28a(3) =696a(4) =26512a(5) =1402656a(6) =97017792a(7) =8418174848a(8) =889241719040

External references