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A260538
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Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00010001.
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1
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75, 131, 310, 566, 976, 2229, 4296, 7576, 16060, 32285, 58636, 118158, 240124, 449449, 881000, 1782816, 3414548, 6616199, 13258972, 25773006, 49827510, 98896019, 193756928, 375388238, 739657558, 1453670523, 2825958650, 5543030018
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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) = a(n-2) + 5*a(n-3) + 4*a(n-4) - 3*a(n-5) - 2*a(n-6) - 10*a(n-8) - 6*a(n-9) + a(n-10) - a(n-11) + a(n-12) + a(n-13) for n>14.
Empirical g.f.: x*(75 + 131*x + 235*x^2 + 60*x^3 - 289*x^4 - 186*x^5 - 207*x^6 - 605*x^7 - 217*x^8 + 133*x^9 - 38*x^10 + 79*x^11 + 45*x^12 - 13*x^13) / (1 - x^2 - 5*x^3 - 4*x^4 + 3*x^5 + 2*x^6 + 10*x^8 + 6*x^9 - x^10 + x^11 - x^12 - x^13). - Colin Barker, Dec 29 2018
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EXAMPLE
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Some solutions for n=4:
..1..0..0..1....0..0..0..0....1..0..0..0....0..0..0..1....0..0..0..1
..1..0..0..1....0..1..1..0....1..1..0..0....1..0..0..1....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..1..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..1..0..0
..1..0..0..1....0..1..0..0....0..1..0..0....1..0..0..1....0..0..0..0
..1..0..0..0....0..1..0..0....0..1..0..0....1..0..0..0....0..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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