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A302220
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Number of nX4 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
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1
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2, 45, 164, 934, 4237, 21777, 105585, 523414, 2578424, 12726069, 62802085, 309849336, 1529212139, 7545987106, 37239443170, 183771070484, 906898467298, 4475474508545, 22086156194245, 108993766999235, 537877222587527
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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) = 5*a(n-1) +11*a(n-2) -42*a(n-3) -95*a(n-4) +21*a(n-5) +327*a(n-6) +1255*a(n-7) +317*a(n-8) -5188*a(n-9) -6921*a(n-10) +6005*a(n-11) +22780*a(n-12) +10157*a(n-13) -27962*a(n-14) -42374*a(n-15) -2355*a(n-16) +48767*a(n-17) +45664*a(n-18) -6331*a(n-19) -46138*a(n-20) -32422*a(n-21) +6577*a(n-22) +23809*a(n-23) +15150*a(n-24) -2372*a(n-25) -6308*a(n-26) -2794*a(n-27) -68*a(n-28) +832*a(n-29) +20*a(n-30) for n>34
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EXAMPLE
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Some solutions for n=5
..0..1..0..0. .0..0..0..1. .0..1..1..0. .0..1..1..0. .0..0..0..1
..1..0..1..0. .0..1..1..0. .0..0..0..0. .0..0..0..0. .1..0..1..0
..0..1..1..0. .1..1..0..0. .1..1..1..1. .1..1..1..1. .1..1..0..0
..0..1..0..0. .1..1..0..1. .0..0..0..0. .0..1..0..0. .0..1..0..1
..0..0..1..1. .0..0..1..1. .1..1..0..0. .0..0..1..1. .1..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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