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A260834
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Number of (n+2)X(1+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000011 or 00010101
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1
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48, 82, 188, 364, 644, 1320, 2584, 4842, 9412, 18210, 35192, 68158, 130812, 253334, 491376, 945170, 1825292, 3533066, 6818232, 13167414, 25439060, 49131310, 94931752, 183337586, 354061772, 684091450, 1321342040, 2551947046, 4929738068
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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) = 4*a(n-3) +3*a(n-4) +4*a(n-5) +12*a(n-8) +12*a(n-9) -8*a(n-11) -12*a(n-12) -12*a(n-13) -8*a(n-14) for n>15
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EXAMPLE
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Some solutions for n=4
..0..0..1....1..0..0....0..0..0....0..0..0....0..1..0....1..0..0....0..0..0
..0..0..1....0..1..0....0..0..1....1..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..0..0....0..0..1
..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..1..0....0..0..0
..0..0..1....0..1..0....1..1..0....1..0..0....0..0..0....0..0..1....1..0..1
..0..0..1....1..0..0....1..0..0....0..0..0....0..1..0....0..1..0....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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