A092088 Number of spanning trees with degrees 1 and 3 in K_5 X P_2n.

1320, 8872800, 57159820320, 368270723329920, 2372720981421121920, 15287133546258050856960, 98493019073706019959014400

Offset

1,1

Links

Table of n, a(n) for n=1..7.

F. Faase, Counting Hamiltonian cycles in product graphs

F. Faase, Results from the counting program

Formula

If b(n) denotes the number of spanning trees with degrees 1 and 3 in P_5 X P_n we have:

b(1) = 0,

b(2) = 1320,

b(3) = 0,

b(4) = 8872800,

b(5) = 0,

b(6) = 57159820320,

b(7) = 0,

b(8) = 368270723329920,

b(9) = 0,

b(10) = 2372720981421121920,

b(11) = 0,

b(12) = 15287133546258050856960,

b(13) = 0,

b(14) = 98493019073706019959014400, and

b(n) = 6288b(n-2) + 990168b(n-4) + 49284576b(n-6) - 334385280b(n-8) - 782880768b(n-10) - 34504704b(n-12).

Crossrefs

Sequence in context: A350612 A013641 A295449 * A068302 A139666 A186469

Adjacent sequences: A092085 A092086 A092087 * A092089 A092090 A092091

Keyword

nonn,more

Author

Ralf Stephan, Mar 28 2004

Extensions

Added recurrence from Faase's web page. - N. J. A. Sloane, Feb 03 2009

Status

approved