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A028470 Number of perfect matchings in graph P_{8} X P_{n}. +0
5
1, 34, 153, 2245, 14824, 167089, 1292697, 12988816, 108435745, 1031151241, 8940739824, 82741005829, 731164253833, 6675498237130, 59554200469113, 540061286536921, 4841110033666048, 43752732573098281 (list; graph; listen)
OFFSET

1,2

REFERENCES

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

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

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 Hamilton cycles in product graphs

F. Faase, Results from the counting program

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

James A. Sellers, Domino Tilings and Products of Fibonacci and Pell Numbers, Journal of Integer Sequences, Vol. 5 (2002), Article 02.1.2

FORMULA

Recurrence from Faase web site: a(1) = 1,

a(2) = 34,

a(3) = 153,

a(4) = 2245,

a(5) = 14824,

a(6) = 167089,

a(7) = 1292697,

a(8) = 12988816,

a(9) = 108435745,

a(10) = 1031151241,

a(11) = 8940739824,

a(12) = 82741005829,

a(13) = 731164253833,

a(14) = 6675498237130,

a(15) = 59554200469113,

a(16) = 540061286536921,

a(17) = 4841110033666048,

a(18) = 43752732573098281,

a(19) = 393139145126822985,

a(20) = 3547073578562247994,

a(21) = 31910388243436817641,

a(22) = 287665106926232833093,

a(23) = 2589464895903294456096,

a(24) = 23333526083922816720025,

a(25) = 210103825878043857266833,

a(26) = 1892830605678515060701072,

a(27) = 17046328120997609883612969,

a(28) = 153554399246902845860302369,

a(29) = 1382974514097522648618420280,

a(30) = 12457255314954679645007780869,

a(31) = 112199448394764215277422176953,

a(32) = 1010618564986361239515088848178, and

a(n) = 153a(n-2) - 7480a(n-4) + 151623a(n-6) - 1552087a(n-8) + 8933976a(n-10)

- 30536233a(n-12) + 63544113a(n-14) - 81114784a(n-16) + 63544113a(n-18) - 30536233a(n-20)

+ 8933976a(n-22) - 1552087a(n-24) + 151623a(n-26) - 7480a(n-28) + 153a(n-30) - a(n-32).

CROSSREFS

Row 8 of array A099390.

Sequence in context: A031398 A159744 A167241 this_sequence A063652 A032771 A074709

Adjacent sequences: A028467 A028468 A028469 this_sequence A028471 A028472 A028473

KEYWORD

nonn

AUTHOR

Per Hakan Lundow (phl(AT)theophys.kth.se)

EXTENSIONS

Added recurrence from Faase's web page. - N. J. A. Sloane (njas(AT)research.att.com), Feb 03 2009

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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