

A145410


Number of 2factors in K_6 X P_n.


0



70, 24400, 6912340, 1997380720, 576043535680, 166162145824000, 47929270990315840, 13825165615038910720, 3987858909906969326080, 1150295005804962553753600, 331801758293292909512074240, 95707976014178819083415941120, 27606896116821809366222931066880
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OFFSET

1,1


REFERENCES

F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Ars Combin. 49 (1998), 129154.


LINKS

Table of n, a(n) for n=1..13.
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), 129154.
F. Faase, Counting Hamiltonian cycles in product graphs.
F. Faase, Results from the counting program
Index entries for linear recurrences with constant coefficients, signature (264,7160,31008,10480).


FORMULA

Recurrence:
a(1) = 70,
a(2) = 24400,
a(3) = 6912340,
a(4) = 1997380720, and
a(n) = 264a(n1) + 7160a(n2)  31008a(n3)  10480a(n4).
G.f.: 10*x*(1048*x^3+3046*x^2592*x7)/(10480*x^4+31008*x^37160*x^2264*x+1). [Colin Barker, Aug 30 2012]


MAPLE

a:= n> (<<26471603100810480>, <1000>, <0100>, <0010>>^n. <<6912340, 24400, 70, 1>>)[4, 1]: seq(a(n), n=1..15); # Alois P. Heinz, Sep 20 2011


MATHEMATICA

a[1] = 70; a[2] = 24400; a[3] = 6912340; a[4] = 1997380720; a[n_] := a[n] = 264*a[n1] + 7160*a[n2]  31008*a[n3]  10480*a[n4]; Array[a, 13] (* JeanFrançois Alcover, Mar 18 2014 *)
LinearRecurrence[{264, 7160, 31008, 10480}, {70, 24400, 6912340, 1997380720}, 20] (* Harvey P. Dale, Jul 11 2021 *)


CROSSREFS

Sequence in context: A004109 A002829 A177637 * A177638 A274646 A005983
Adjacent sequences: A145407 A145408 A145409 * A145411 A145412 A145413


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane, Feb 03 2009


STATUS

approved



