0,3

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.

R. P. Stanley, Enumerative Combinatorics I, p. 292.

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.

a(1) = 1,

a(2) = 13,

a(3) = 41,

a(4) = 281,

a(5) = 1183,

a(6) = 6728,

a(7) = 31529,

a(8) = 167089,

a(9) = 817991,

a(10) = 4213133,

a(11) = 21001799,

a(12) = 106912793,

a(13) = 536948224,

a(14) = 2720246633, and

a(n) = 40a(n-2) - 416a(n-4) + 1224a(n-6) - 1224a(n-8) + 416a(n-10) - 40a(n-12) + a(n-14).

G.f.: (1-8*x^2-2*x^3+8*x^4-x^6)/(1-x-20*x^2-10*x^3+38*x^4+10*x^5-20*x^6+x^7+x^8).

Row 6 of array A099390.

Sequence in context: A141970 A167240 A147247 this_sequence A146995 A102130 A080186

Adjacent sequences: A028465 A028466 A028467 this_sequence A028469 A028470 A028471

nonn

N. J. A. Sloane (njas(AT)research.att.com), Per Hakan Lundow (phl(AT)theophys.kth.se)

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