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A308136
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Number of (undirected) Hamiltonian paths in the 2n-crossed prism graph.
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1
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72, 288, 960, 2880, 8064, 21504, 55296, 138240, 337920, 811008, 1916928, 4472832, 10321920, 23592960, 53477376, 120324096, 268959744, 597688320, 1321205760, 2906652672, 6366953472, 13891534848, 30198988800, 65431142400, 141331267584, 304405807104
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OFFSET
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2,1
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LINKS
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FORMULA
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G.f.: 24*x^2*(3 - 6*x + 4*x^2) / (1 - 2*x)^3.
a(n) = 3*2^n*n*(1+n).
a(n) = 6*a(n-1) - 12*a(n-2) + 8*a(n-3) for n>4.
(End)
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PROG
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(PARI) Vec(24*x^2*(3 - 6*x + 4*x^2) / (1 - 2*x)^3 + O(x^30)) \\ Colin Barker, Jul 19 2019
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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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