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A297854
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Number of nX4 0..1 arrays with every element equal to 1, 2 or 4 king-move adjacent elements, with upper left element zero.
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1
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2, 13, 19, 30, 53, 90, 145, 244, 406, 771, 1396, 2472, 4358, 7688, 13953, 25626, 46458, 83576, 150333, 271566, 494639, 900920, 1633015, 2955455, 5353266, 9717165, 17670119, 32099391, 58228907, 105619960, 191684445, 348131289, 632389497
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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) +a(n-2) -a(n-3) -2*a(n-4) +2*a(n-5) +a(n-6) -22*a(n-7) +22*a(n-9) +16*a(n-10) +14*a(n-11) +10*a(n-12) -4*a(n-13) -40*a(n-14) -26*a(n-15) -24*a(n-16) -12*a(n-17) -9*a(n-18) +33*a(n-19) +55*a(n-20) +13*a(n-21) +6*a(n-22) +10*a(n-23) +31*a(n-24) -24*a(n-25) -29*a(n-26) -4*a(n-27) -31*a(n-28) -25*a(n-29) +6*a(n-30) +22*a(n-31) +10*a(n-32) for n>37
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EXAMPLE
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Some solutions for n=7
..0..1..0..0. .0..1..1..0. .0..1..0..0. .0..0..1..1. .0..1..1..1
..0..1..1..1. .0..1..0..0. .0..0..1..1. .1..0..1..0. .1..0..0..0
..1..1..0..0. .0..1..1..1. .1..1..0..1. .0..1..0..1. .1..0..0..1
..0..0..1..1. .1..1..0..0. .0..0..0..0. .1..1..0..0. .0..1..1..1
..1..0..0..0. .0..0..1..1. .1..0..1..1. .1..1..0..0. .1..1..0..0
..1..0..1..1. .1..1..1..0. .1..1..0..0. .0..1..0..1. .0..0..1..1
..1..0..0..1. .0..0..1..0. .0..0..1..0. .0..0..0..1. .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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