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A117633
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Number of self-avoiding walks of n steps on a Manhattan square lattice.
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0
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2, 4, 8, 14, 26, 48, 88, 154, 278, 500, 900, 1576, 2806, 4996, 8894, 15564, 27538, 48726, 86212, 150792, 265730, 468342, 825462, 1442866, 2535802, 4457332, 7835308, 13687192
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OFFSET
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1,1
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LINKS
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Table of n, a(n) for n=1..28.
A. Malakis, Self-avoiding walks on oriented square lattices,J. Phys. A: Math. Gen. 8 (1975) no 12, 1885-1898
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EXAMPLE
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On each crossing, the first step may follow a street or an avenue. So a(1)=2.
On the next crossing, each of these 2 paths faces again two choices, giving a(2)=4. At n=4, a(4) becomes less than 16 considering the 2 cases of having moved around a block.
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CROSSREFS
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Sequence in context: A120545 A130708 A054193 * A135491 A164154 A164156
Adjacent sequences: A117630 A117631 A117632 * A117634 A117635 A117636
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KEYWORD
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nonn
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AUTHOR
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R. J. Mathar, Apr 08 2006
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STATUS
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approved
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