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
Andrew Howroyd and Colin Barker, Table of n, a(n) for n = 1..427 (first 30 terms from Andrew Howroyd)
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, Results from the counting program
Index entries for linear recurrences with constant coefficients, signature (493,-76229,3141623,83807874,375481728,-11713248,-1292308992,1074456576,-238878720).
FORMULA
Recurrence:
a(1) = 360,
a(2) = 275040,
a(3) = 102430080,
a(4) = 31321626480,
a(5) = 8516117133360,
a(6) = 2155827631204800,
a(7) = 520736224355831520,
a(8) = 121804259414668451280,
a(9) = 27852572730572966535120,
a(10) = 6266130842526092431103520, and
a(n) = 493*a(n-1) - 76229*a(n-2) + 3141623*a(n-3) + 83807874*a(n-4) + 375481728*a(n-5) - 11713248*a(n-6) - 1292308992*a(n-7) + 1074456576*a(n-8) - 238878720*a(n-9).
G.f.: 360*x*(1 +271*x -15895*x^2 +1829547*x^3 -32069382*x^4 +43786376*x^5 -451478784*x^6 -35025408*x^7 +155602944*x^8 -39813120*x^9) / ((1 -145*x -516*x^2 +288*x^3)^2*(1 -203*x -2634*x^2 +2880*x^3)). - Colin Barker, Dec 22 2015
PROG
(PARI) Vec(360*x*(1 +271*x -15895*x^2 +1829547*x^3 -32069382*x^4 +43786376*x^5 -451478784*x^6 -35025408*x^7 +155602944*x^8 -39813120*x^9) / ((1 -145*x -516*x^2 +288*x^3)^2*(1 -203*x -2634*x^2 +2880*x^3)) + O(x^20)) \\ Colin Barker, Dec 22 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Feb 03 2009
EXTENSIONS
a(11)-a(12) from Andrew Howroyd, Dec 21 2015
a(13) from Vincenzo Librandi, Dec 22 2015
STATUS
approved