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A305178
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Number of nX4 0..1 arrays with every element unequal to 1, 2, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
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1
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2, 1, 9, 10, 13, 47, 71, 118, 241, 453, 870, 1608, 3110, 6075, 11491, 22105, 42831, 82321, 158514, 305836, 589983, 1137829, 2194384, 4234349, 8170446, 15762684, 30415495, 58692610, 113253536, 218539740, 421716458, 813790085, 1570376360
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) -2*a(n-5) -5*a(n-6) -3*a(n-7) -2*a(n-9) +a(n-10) +2*a(n-11) for n>18
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EXAMPLE
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Some solutions for n=5
..0..1..0..0. .0..1..0..0. .0..0..1..0. .0..0..1..0. .0..1..0..0
..0..0..0..1. .0..0..0..1. .1..0..0..0. .1..0..0..0. .0..0..0..1
..1..0..0..0. .0..0..0..0. .0..0..0..1. .0..0..0..0. .0..0..0..0
..0..0..0..1. .1..0..1..0. .1..0..0..0. .0..0..0..1. .1..0..0..0
..0..1..0..0. .0..0..0..1. .0..0..1..0. .0..1..0..0. .0..0..1..0
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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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