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A269279
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Number of 4Xn 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three exactly once.
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1
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0, 20412, 1365336, 74853576, 3719884392, 174924572760, 7934992835112, 350946381867480, 15232155757251048, 651580499598523992, 27551808205246504872, 1154085846201751972824, 47965168186749101620584
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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) = 96*a(n-1) -3108*a(n-2) +40720*a(n-3) -265326*a(n-4) +931200*a(n-5) -1766452*a(n-6) +1678992*a(n-7) -622521*a(n-8) for n>12
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EXAMPLE
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Some solutions for n=2
..0..3. .2..0. .1..3. .1..3. .0..2. .0..2. .0..1. .0..2. .0..1. .1..3
..3..3. .0..0. .0..0. .3..1. .3..3. .3..2. .3..2. .2..3. .3..1. .2..2
..2..2. .1..3. .2..2. .2..2. .0..2. .1..0. .0..1. .3..2. .3..0. .1..3
..0..2. .1..2. .0..1. .3..2. .2..3. .0..2. .1..2. .1..3. .0..0. .1..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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