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A208874
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Number of 3Xn 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors
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1
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5, 143, 6520, 307165, 14493405, 683903931, 32271626438, 1522813452263, 71857577327143, 3390770839381669, 160001593732718856, 7550056082308516761, 356267369073405009281, 16811323900505484274607, 793282337427660173475274
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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) = 61*a(n-1) -722*a(n-2) +3476*a(n-3) -7851*a(n-4) +8583*a(n-5) -4266*a(n-6) +720*a(n-7) for n>8
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EXAMPLE
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Some solutions for n=4
..0..1..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..2..2..1..2....1..1..1..2....1..2..2..1....1..1..1..0....1..1..1..0
..1..2..3..2....2..0..1..3....1..0..1..2....0..0..1..1....2..2..3..2
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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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