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A206250
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Number of (n+1) X 4 0..3 arrays with every 2 X 2 subblock having zero permanent.
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1
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1600, 99856, 1364224, 49336576, 944701696, 27285753856, 603269103616, 15860529270784, 372641945092096, 9417680785309696, 227009527113908224, 5642600260896292864, 137487696199369621504, 3393605721164360974336
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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) = 28*a(n-1) +192*a(n-2) -8352*a(n-3) +25920*a(n-4) +373248*a(n-5) -1679616*a(n-6).
Empirical g.f.: 16*x*(100 + 3441*x - 108684*x^2 + 333072*x^3 + 5866992*x^4 - 26873856*x^5) / ((1 - 40*x + 432*x^2 - 1296*x^3)*(1 + 12*x - 144*x^2 - 1296*x^3)). - Colin Barker, Jun 14 2018
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EXAMPLE
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Some solutions for n=4:
..1..0..0..1....2..0..3..3....2..1..2..0....0..0..1..1....1..0..0..0
..0..0..0..1....0..0..0..0....0..0..0..0....3..0..0..0....0..0..1..2
..1..0..0..0....2..1..1..0....2..0..1..3....3..0..1..1....1..0..0..0
..1..0..0..3....0..0..0..0....2..0..0..0....1..0..0..0....1..0..3..0
..2..0..0..1....2..1..1..0....0..0..0..1....3..0..0..2....1..0..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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