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A098631 Consider the family of multigraphs enriched by the species of parts. Sequence gives number of those multigraphs with n arcs. 0
1, 2, 28, 696, 26512, 1402656, 97017792, 8418174848, 889241719040, 111774837350912, 16420543334734848, 2778708477919836160, 535183812199464341504, 116142946557502449852416 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

G. Paquin, D\'enombrement de multigraphes enrichis, M\'emoire, Math. Dept., Univ. Qu\'ebec \`a Montr\'eal, 2004.

LINKS

Table of n, a(n) for n=0..13.

FORMULA

a(n) = 2^n*A020556(n). - Vladeta Jovovic, Aug 11 2005

CROSSREFS

Sequence in context: A012745 A143585 A151332 * A089836 A090249 A009256

Adjacent sequences:  A098628 A098629 A098630 * A098632 A098633 A098634

KEYWORD

nonn,changed

AUTHOR

N. J. A. Sloane, Oct 26 2004

EXTENSIONS

More terms from Vladeta Jovovic, Aug 11 2005

STATUS

approved

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Last modified May 22 21:43 EDT 2013. Contains 225583 sequences.