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A220680
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Number of ways to reciprocally link elements of an nX7 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without consecutive collinear links
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1
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1, 441, 22000, 2316754, 215926776, 21051034046, 2045717834201, 198460804181024, 19267871745544463, 1870273847823355410, 181541549823743511322, 17622155633363587138681, 1710539337273283386055832
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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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EXAMPLE
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Some solutions for n=3 0=self 2=n 3=ne 4=w 6=e 7=sw 8=s (reciprocal directions total 10)
.00.00.00.00.78.00.00...00.78.00.67.48.68.47...00.00.00.00.68.48.00
.68.48.00.38.27.78.00...38.27.38.00.27.23.78...00.00.68.48.26.24.78
.26.24.00.23.36.24.00...23.00.26.34.00.36.24...00.00.26.24.00.36.24
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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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