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A098624
Consider the family of multigraphs enriched by the species of derangements. Sequence gives number of those multigraphs with n labeled edges.
3
1, 0, 1, 2, 15, 84, 750, 6852, 79639, 1006184, 14875218, 241078100, 4392257716, 87279581232, 1905609327583, 45008114794874, 1150897256534370, 31580332783936416, 928535967078634497, 29090873853321687666, 969132936087009709174, 34198721664081728281400
OFFSET
0,4
REFERENCES
G. Paquin, Dénombrement de multigraphes enrichis, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004.
LINKS
G. Paquin, Dénombrement de multigraphes enrichis, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004. [Cached copy, with permission]
FORMULA
E.g.f.: B(R(x)) where B(x) is the e.g.f. of A014500 and 1 + R(x) is the e.g.f. of A000166. - Andrew Howroyd, Jan 12 2021
PROG
(PARI) \\ R(n) is A000166 as e.g.f.; EnrichedGnSeq defined in A098620.
R(n)={exp(-x + O(x*x^n))/(1-x)}
EnrichedGnSeq(R(20)) \\ Andrew Howroyd, Jan 12 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 26 2004
EXTENSIONS
Terms a(14) and beyond from Andrew Howroyd, Jan 12 2021
STATUS
approved