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A199642
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Number of nX3 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors
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1
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1, 13, 112, 1265, 12748, 134748, 1396083, 14584050, 151837464, 1582988477, 16494233432, 171904221068, 1791430664487, 18669394073270, 194560012081184, 2027588187779377, 21130256645906468, 220206564513115724
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 7*a(n-1) +41*a(n-2) -44*a(n-3) -111*a(n-4) -140*a(n-5) +291*a(n-6) -225*a(n-7) +511*a(n-8) +2150*a(n-9) -3007*a(n-10) -6248*a(n-11) -624*a(n-12) +19900*a(n-13) -14308*a(n-14) +15248*a(n-15) -13312*a(n-16) -1648*a(n-17) +21440*a(n-18) -5632*a(n-19) -3968*a(n-20) +5632*a(n-21) -14336*a(n-22) -8192*a(n-23) for n>24
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EXAMPLE
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Some solutions for n=4
..0..1..1....0..0..0....0..0..1....0..1..1....0..0..1....0..0..1....0..1..2
..0..2..1....0..1..2....2..2..1....0..2..2....1..1..1....1..0..1....0..1..2
..0..2..0....2..1..2....0..0..1....1..2..2....0..0..2....1..0..0....1..2..2
..0..2..0....2..1..1....0..0..1....1..1..1....0..0..2....1..2..2....1..0..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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