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A304013
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Number of nX2 0..1 arrays with every element unequal to 1, 2, 3 or 5 king-move adjacent elements, with upper left element zero.
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8
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1, 7, 16, 45, 120, 333, 928, 2613, 7400, 21053, 60080, 171845, 492280, 1411789, 4051904, 11635413, 33424648, 96042845, 276020944, 793366629, 2280573208, 6556026349, 18847591392, 54185601013, 155783294760, 447882509949
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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) = 2*a(n-1) +5*a(n-2) -2*a(n-3) -12*a(n-4) -8*a(n-5) for n>6
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EXAMPLE
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Some solutions for n=5
..0..0. .0..0. .0..0. .0..1. .0..1. .0..0. .0..0. .0..1. .0..1. .0..0
..0..1. .1..0. .1..0. .0..0. .1..1. .1..0. .1..0. .1..1. .0..0. .0..1
..0..0. .1..1. .1..1. .1..0. .0..0. .1..1. .0..0. .0..0. .0..1. .0..0
..1..1. .0..1. .0..0. .1..1. .0..1. .0..0. .1..0. .0..0. .1..1. .0..0
..0..1. .1..1. .1..0. .0..0. .0..0. .0..1. .1..1. .0..1. .1..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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