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A261287
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Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00010101 or 01010101.
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1
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96, 133, 271, 504, 1086, 2104, 4715, 9080, 20093, 38864, 86229, 166296, 368773, 712284, 1579561, 3049076, 6762309, 13056148, 28953755, 55898492, 123967937, 239336000, 530772749, 1024728804, 2272547259, 4387441960, 9730031919
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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) = 2*a(n-2) +9*a(n-4) +4*a(n-6) -4*a(n-8) +6*a(n-10) -8*a(n-12) -a(n-16) +3*a(n-18) +4*a(n-20) -4*a(n-22) for n>26
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EXAMPLE
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Some solutions for n=4
..0..1..0..1..0....0..1..0..1..0....1..0..1..0..1....1..0..1..0..1
..1..0..0..0..1....1..0..1..0..0....0..1..0..0..0....0..1..0..1..0
..0..1..0..1..0....0..1..0..1..0....1..0..1..0..1....1..0..1..0..0
..1..0..1..0..1....1..0..1..0..1....0..1..0..1..0....0..1..0..1..0
..0..1..0..1..0....0..1..0..1..0....1..0..1..0..1....0..0..1..0..1
..1..0..0..0..1....1..0..1..0..1....0..1..0..0..0....0..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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