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A188786
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Number of 3-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, 192, 1944, 7936, 22200, 50112, 98392, 175104, 289656, 452800, 676632, 974592, 1361464, 1853376, 2467800, 3223552, 4140792, 5241024, 6547096, 8083200, 9874872, 11948992, 14333784, 17058816, 20155000, 23654592, 27591192, 31999744, 36916536
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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) = 56*n^4 - 112*n^3 + 48*n^2 for n>1.
G.f.: 8*x^2*(24 + 123*x + 17*x^2 + 5*x^3 - x^4) / (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>6.
(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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