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A259738
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Number of (n+2) X (4+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 or 01010101.
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1
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62, 136, 374, 868, 1882, 4456, 10570, 24150, 55686, 130032, 301564, 697220, 1617512, 3753468, 8697990, 20161962, 46756582, 108404418, 251306798, 582661346, 1350925528, 3132018192, 7261427776, 16835543314, 39032675868, 90495655752
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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) + 4*a(n-3) + 5*a(n-4) + 3*a(n-5) + 5*a(n-6) + a(n-7) - 4*a(n-8) - a(n-9) + a(n-10) for n>11.
Empirical g.f.: 2*x*(31 + 37*x + 119*x^2 + 123*x^3 + 80*x^4 + 106*x^5 + 27*x^6 - 76*x^7 - 30*x^8 + 16*x^9 + 3*x^10) / (1 - x - 4*x^3 - 5*x^4 - 3*x^5 - 5*x^6 - x^7 + 4*x^8 + x^9 - x^10). - Colin Barker, Dec 26 2018
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EXAMPLE
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Some solutions for n=4:
..0..0..0..1..0..1....0..0..1..0..1..0....1..0..1..0..1..0....0..1..0..1..0..1
..1..0..1..0..1..0....0..0..0..1..0..0....0..0..0..1..0..1....1..0..1..0..1..0
..0..1..0..1..0..1....1..0..1..0..1..0....1..0..1..0..0..0....0..0..0..1..0..1
..1..0..1..0..1..0....0..1..0..1..0..1....0..1..0..1..0..1....1..0..1..0..1..0
..0..1..0..1..0..1....1..0..1..0..0..0....1..0..1..0..1..0....0..1..0..1..0..0
..1..0..1..0..1..0....0..1..0..1..0..0....0..1..0..1..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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