Consider the family of directed multigraphs enriched by the species of involutions. Sequence gives number of those multigraphs with n labeled loops and arcs.
A099698
Consider the family of directed multigraphs enriched by the species of involutions. Sequence gives number of those multigraphs with n labeled loops and arcs.
Terms
- a(0) =1a(1) =2a(2) =17a(3) =248a(4) =5403a(5) =160420a(6) =6142567a(7) =291996934a(8) =16759322733
External references
- oeis: A099698