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A188785
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Number of 2-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, 64, 432, 1536, 4000, 8640, 16464, 28672, 46656, 72000, 106480, 152064, 210912, 285376, 378000, 491520, 628864, 793152, 987696, 1216000, 1481760, 1788864, 2141392, 2543616, 3000000, 3515200, 4094064, 4741632, 5463136, 6264000, 7149840
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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) = 8*n^4 - 8*n^3.
G.f.: 16*x^2*(4 + 7*x + x^2) / (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>5.
(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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