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A145409 Number of perfect matchings (or domino tilings) in K_6 X P_n. 0
15, 376, 8805, 207901, 4903920, 115686901, 2729093235, 64380355576, 1518756918825, 35828050696201, 845197277027040, 19938523685081401, 470357320740846855, 11095907233164566776, 261756651587724670845 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Ars Combin. 49 (1998), 129-154.

LINKS

Table of n, a(n) for n=1..15.

F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Preliminary version of paper that appeared in Ars Combin. 49 (1998), 129-154.

F. Faase, Counting Hamiltonian cycles in product graphs.

F. Faase, Results from the counting program

FORMULA

Recurrence:

a(1) = 15,

a(2) = 376,

a(3) = 8805,

a(4) = 207901, and

a(n) = 21a(n-1) + 62a(n-2) - 21a(n-3) - a(n-4).

G.f.: x(15+61x-21x^2-x^3)/(1-21x-62x^2+21x^3+x^4). - R. J. Mathar, Feb 19 2009

CROSSREFS

Sequence in context: A087330 A035274 A324415 * A164323 A129615 A286139

Adjacent sequences:  A145406 A145407 A145408 * A145410 A145411 A145412

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Feb 03 2009

EXTENSIONS

More terms from R. J. Mathar, Feb 19 2009

STATUS

approved

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Last modified November 26 07:17 EST 2020. Contains 338632 sequences. (Running on oeis4.)