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A188787
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Number of 4-step self-avoiding walks on an n X n X n X n 4-cube summed over all starting positions.
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1
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0, 576, 8928, 41984, 125840, 296064, 597632, 1084928, 1821744, 2881280, 4346144, 6308352, 8869328, 12139904, 16240320, 21300224, 27458672, 34864128, 43674464, 54056960, 66188304, 80254592, 96451328, 114983424, 136065200, 159920384
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 392*n^4 - 1128*n^3 + 912*n^2 - 192*n for n>2.
G.f.: 16*x^2*(36 + 378*x + 194*x^2 - 35*x^3 + 19*x^4 - 4*x^5) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>7.
(End)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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