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A302428
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Number of 3 X n 0..1 arrays with every element equal to 0, 1, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
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1
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4, 6, 11, 21, 38, 88, 188, 377, 735, 1557, 3288, 6781, 13628, 28203, 58716, 121753, 248505, 511788, 1057997, 2191020, 4502367, 9272331, 19120457, 39518063, 81408758, 167766247, 345763679, 713697958, 1471345608, 3033391563, 6252203749
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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) = a(n-1) +a(n-2) -a(n-3) +12*a(n-4) -5*a(n-5) -7*a(n-6) +2*a(n-7) -26*a(n-8) +7*a(n-9) +14*a(n-10) -2*a(n-11) +18*a(n-12) -3*a(n-13) -9*a(n-14) +a(n-15) -3*a(n-16) +a(n-18) for n>19.
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EXAMPLE
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Some solutions for n=5
..0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0. .0..0..0..1..0
..0..1..0..1..0. .0..1..1..1..0. .0..1..0..1..0. .0..1..1..1..0
..0..0..1..1..0. .0..0..0..1..0. .0..1..1..0..0. .0..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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