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A302821
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Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
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1
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4, 25, 75, 220, 731, 2419, 7900, 25645, 83685, 273504, 893195, 2915411, 9518108, 31079021, 101478805, 331335348, 1081839931, 3532345439, 11533574036, 37658571753, 122959986781, 401480186136, 1310884882811, 4280209057195
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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) = 6*a(n-1) -9*a(n-2) +2*a(n-4) -18*a(n-5) +37*a(n-6) +34*a(n-7) +5*a(n-8) -52*a(n-9) -118*a(n-10) -24*a(n-11) +190*a(n-12) +10*a(n-13) -68*a(n-14) +12*a(n-15) for n>16
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EXAMPLE
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Some solutions for n=5
..0..1..1..1..1. .0..1..1..1..0. .0..0..0..0..0. .0..1..0..0..0
..0..1..0..1..0. .0..1..0..1..0. .0..0..0..0..0. .0..0..1..1..1
..0..1..0..0..0. .0..1..1..1..0. .1..1..0..1..1. .1..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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