A099692 Consider the family of multigraphs enriched by the species of directed sets. Sequence gives number of those multigraphs with n labeled edges.

1, 1, 4, 23, 220, 3016, 55011, 1265824, 35496711, 1183686987, 46072834777, 2062557088117, 104926356851165, 6004962409831577, 383331023991407286, 27094756978689827593, 2107021273883402908850, 179261681391054814324774, 16602830645109035036038335

Offset

0,3

References

G. Paquin, Dénombrement de multigraphes enrichis, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004.

Links

Andrew Howroyd, Table of n, a(n) for n = 0..100

G. Paquin, Dénombrement de multigraphes enrichis, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004. [Cached copy, with permission]

Formula

E.g.f.: B(2*exp(x) - x - 2) where B(x) is the e.g.f. of A014500. - Andrew Howroyd, Jan 12 2021

Prog

(PARI) \\ R(n) is e.g.f. of 1, 1, 2, 2, 2, 2, ...; EnrichedGnSeq defined in A098620.
R(n)={2*exp(x + O(x*x^n)) - x - 1}
EnrichedGnSeq(R(20)) \\ Andrew Howroyd, Jan 12 2021

Crossrefs

Cf. A000110, A014500, A098620, A099693, A099694, A099695.

Sequence in context: A056785 A188404 A105747 * A283499 A305787 A295234

Adjacent sequences: A099689 A099690 A099691 * A099693 A099694 A099695

Keyword

nonn

Author

N. J. A. Sloane, Oct 26 2004

Extensions

Terms a(11) and beyond from Andrew Howroyd, Jan 12 2021

Status

approved