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A259766
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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 or 00000101.
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1
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49, 87, 167, 299, 564, 1086, 2045, 3870, 7371, 14001, 26647, 50766, 96574, 183815, 350088, 666497, 1268925, 2416285, 4600654, 8759750, 16679685, 31759384, 60472021, 115144725, 219245665, 417461876, 794885812, 1513533557, 2881900030
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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-1) + a(n-2) + a(n-3) + 2*a(n-4) - 2*a(n-5) + 2*a(n-6) - 4*a(n-7) - 3*a(n-8) + 2*a(n-9) - 4*a(n-10) + 2*a(n-11) for n>12.
Empirical g.f.: x*(49 + 38*x + 31*x^2 - 4*x^3 - 87*x^4 - 20*x^5 - 162*x^6 - 67*x^7 + x^8 - 96*x^9 + 78*x^10 - 6*x^11) / (1 - x - x^2 - x^3 - 2*x^4 + 2*x^5 - 2*x^6 + 4*x^7 + 3*x^8 - 2*x^9 + 4*x^10 - 2*x^11). - Colin Barker, Dec 27 2018
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EXAMPLE
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Some solutions for n=4:
..0..0..0..0....0..0..1..0....0..0..0..1....0..1..0..0....0..0..0..1
..0..1..0..0....0..0..0..1....1..0..0..0....1..0..0..0....0..0..0..0
..1..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....1..0..0..1
..0..0..0..0....1..0..0..0....1..0..0..1....0..0..0..1....0..0..0..0
..1..0..0..1....0..0..0..1....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..0..0....1..0..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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