Consider the family of directed multigraphs enriched by the species of directed graphs. Sequence gives number of those multigraphs with n labeled loops and arcs.
A099706
Consider the family of directed multigraphs enriched by the species of directed graphs. Sequence gives number of those multigraphs with n labeled loops and arcs.
Terms
- a(0) =1a(1) =4a(2) =84a(3) =3568a(4) =305712a(5) =87782720a(6) =144600947392
External references
- oeis: A099706