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A204033
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Number of (n+1)X3 0..1 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards
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1
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44, 164, 603, 1758, 5130, 13040, 33223, 77574, 181559, 401370, 889157, 1896644, 4052667, 8444892, 17621165, 36165014, 74299430, 151007392, 307137335, 620376066, 1253727656, 2522563936, 5077320907, 10191401694, 20461362545
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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) = 4*a(n-1) +8*a(n-2) -50*a(n-3) -9*a(n-4) +270*a(n-5) -128*a(n-6) -820*a(n-7) +709*a(n-8) +1520*a(n-9) -1824*a(n-10) -1722*a(n-11) +2797*a(n-12) +1070*a(n-13) -2696*a(n-14) -160*a(n-15) +1608*a(n-16) -240*a(n-17) -544*a(n-18) +160*a(n-19) +80*a(n-20) -32*a(n-21)
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EXAMPLE
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Some solutions for n=4
..1..1..0....1..1..0....1..1..1....1..0..1....0..0..1....1..0..0....1..1..1
..0..1..1....0..1..1....0..1..0....0..0..0....1..1..0....0..1..1....0..1..1
..1..1..1....1..1..1....1..1..1....0..1..1....0..1..1....1..1..0....1..1..1
..0..1..1....0..1..1....1..1..1....0..1..0....1..1..1....0..1..1....0..1..1
..1..1..1....1..1..1....1..1..1....1..1..1....1..1..1....1..1..0....1..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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