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A232840
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Number of (1+1) X (n+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally.
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1
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4, 16, 216, 710, 3648, 25642, 139456, 683250, 3950740, 22616130, 120525288, 658213410, 3693117580, 20305930298, 110933224304, 613037501594, 3386085231380, 18604669612418, 102411236923656, 564815468453874
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = 2*a(n-1) + 3*a(n-2) + 66*a(n-3) + 150*a(n-4) - 86*a(n-5) - 36*a(n-6) - 176*a(n-7) - 512*a(n-8).
Empirical g.f.: 2*x*(2 + 4*x + 86*x^2 - 17*x^3 - 38*x^4 - 48*x^5 - 256*x^6) / (1 - 2*x - 3*x^2 - 66*x^3 - 150*x^4 + 86*x^5 + 36*x^6 + 176*x^7 + 512*x^8). - Colin Barker, Oct 06 2018
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EXAMPLE
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Some solutions for n=5:
..1..0..0..2..1..0....0..1..0..0..1..2....0..2..2..0..1..0....0..1..0..2..2..0
..1..2..0..1..2..0....0..1..2..1..2..0....2..1..1..1..0..2....2..1..2..1..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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