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A296630
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Number of nX3 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 0, 2 or 4 neighboring 1s.
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1
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5, 19, 71, 260, 966, 3581, 13275, 49209, 182422, 676247, 2506882, 9293135, 34450119, 127708318, 473421137, 1754995884, 6505857719, 24117540693, 89404932324, 331428565852, 1228622307611, 4554564483230, 16883998852534, 62589830114818
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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) = 2*a(n-1) +4*a(n-2) +6*a(n-3) +8*a(n-4) +6*a(n-5) +3*a(n-6) -2*a(n-7) -6*a(n-8) -8*a(n-9) -7*a(n-10) -4*a(n-11) -a(n-12)
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EXAMPLE
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Some solutions for n=7
..1..1..1. .0..1..0. .0..0..1. .0..1..0. .0..0..1. .1..1..1. .1..0..0
..1..1..0. .1..1..0. .0..1..1. .1..1..0. .0..0..0. .1..1..0. .0..0..0
..1..0..0. .0..0..0. .1..1..1. .0..0..0. .1..1..0. .1..0..0. .1..0..1
..0..0..0. .0..1..1. .0..0..0. .0..0..1. .1..0..0. .0..1..0. .0..1..1
..1..0..0. .0..1..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0
..0..1..0. .1..1..0. .0..1..1. .0..0..1. .0..0..0. .1..0..1. .0..0..0
..0..0..1. .0..0..0. .0..1..0. .0..1..1. .0..0..1. .0..0..0. .1..0..1
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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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