A145413 Number of spanning trees with degrees 1 and 3 in K_6 X P_n.

90, 50400, 28528560, 15618720960, 8555317093440, 4687533591644160, 2568304253243013120, 1407173820392030238720, 770990635166535068405760, 422425827340189334775152640

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..10.

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) = 90,

a(2) = 50400,

a(3) = 28528560,

a(4) = 15618720960,

a(5) = 8555317093440,

a(6) = 4687533591644160,

a(7) = 2568304253243013120,

a(8) = 1407173820392030238720,

a(9) = 770990635166535068405760,

a(10) = 422425827340189334775152640,

a(11) = 231447142314556654419647815680,

a(12) = 126809906538716706435229846241280,

a(13) = 69479157253021351235506090834329600, and

a(n) = 516a(n-1) + 14600a(n-2) + 1541184a(n-3) + 19457664a(n-4) + 56414208a(n-5)

+ 82785024a(n-6) + 219608064a(n-7) - 213166080a(n-8) + 173408256a(n-9) + 21233664a(n-10).

Crossrefs

Sequence in context: A246634 A270508 A134648 * A367459 A279442 A172572

Adjacent sequences: A145410 A145411 A145412 * A145414 A145415 A145416

Keyword

nonn

Author

N. J. A. Sloane, Feb 03 2009

Status

approved