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A145406
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Number of Hamiltonian cycles in O_6 X P_n.
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1
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16, 1568, 105080, 7178840, 490094648, 33459179864, 2284284179000, 155949857160056, 10646817995958872, 726866542276644152, 49623743965671329432, 3387851582022139415576, 231291261492682043873912, 15790434246516135813006104, 1078025222761987287876732152, 73597620101387422536267848888
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OFFSET
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1,1
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REFERENCES
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F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Ars Combin. 49 (1998), 129-154.
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LINKS
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FORMULA
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Recurrence:
a(1) = 16,
a(2) = 1568,
a(3) = 105080,
a(4) = 7178840,
a(5) = 490094648,
a(6) = 33459179864,
a(7) = 2284284179000,
a(8) = 155949857160056,
a(9) = 10646817995958872, and
a(n) = 76a(n-1) - 542a(n-2) + 936a(n-3) + 2987a(n-4) - 9940a(n-5) + 4896a(n-6) + 9600a(n-7) - 8192a(n-8).
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MAPLE
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f:= gfun:-rectoproc({a(1) = 16,
a(2) = 1568, a(3) = 105080, a(4) = 7178840, a(5) = 490094648,
a(6) = 33459179864, a(7) = 2284284179000, a(8) = 155949857160056,
a(9) = 10646817995958872,
a(n) = 76*a(n-1) - 542*a(n-2) + 936*a(n-3) + 2987*a(n-4) - 9940*a(n-5) + 4896*a(n-6) + 9600*a(n-7) - 8192*a(n-8)}, a(n), remember):
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MATHEMATICA
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a[n_] := a[n] = If[n<10, {16, 1568, 105080, 7178840, 490094648, 33459179864, 2284284179000, 155949857160056, 10646817995958872}[[n]], 76a[n-1] - 542a[n-2] + 936a[n-3] + 2987a[n-4] - 9940a[n-5] + 4896a[n-6] + 9600a[n-7] - 8192a[n-8]];
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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