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A028481 Number of perfect matchings in graph C_{10} X P_{n}. 1
1, 2, 125, 1452, 37584, 631750, 13344409, 248864088, 4964424625, 95464562688, 1872712598261, 36340255066500, 709361528836661, 13802335712555182, 269027285006250000, 5238744073324512432, 102066374099541816889, 1987998048123941635250, 38727167228395071878789 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

Per Hakan Lundow, "Computation of matching polynomials and the number of 1-factors in polygraphs", Research report, No 12, 1996, Department of Math., Umea University, Sweden.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..500

Per Hakan Lundow, Enumeration of matchings in polygraphs, 1998.

FORMULA

G.f.: -(x^16 +8*x^15 -130*x^14 -320*x^13 +3030*x^12 +1910*x^11 -16645*x^10 -5140*x^9 +27980*x^8 +5140*x^7 -16645*x^6 -1910*x^5 +3030*x^4 +320*x^3 -130*x^2 -8*x +1) / (x^18 +10*x^17 -235*x^16 -588*x^15 +8165*x^14 +6430*x^13 -72855*x^12 -40880*x^11 +199465*x^10 +70490*x^9 -199465*x^8 -40880*x^7 +72855*x^6 +6430*x^5 -8165*x^4 -588*x^3 +235*x^2 +10*x -1). - Alois P. Heinz, Dec 10 2013

CROSSREFS

Sequence in context: A183720 A042921 A123006 * A049659 A209602 A237994

Adjacent sequences:  A028478 A028479 A028480 * A028482 A028483 A028484

KEYWORD

nonn

AUTHOR

Per H. Lundow

STATUS

approved

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Last modified September 23 09:53 EDT 2021. Contains 347612 sequences. (Running on oeis4.)