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A259421
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Number of (n+1) X (2+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0001 0011 or 0111.
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1
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43, 243, 1366, 7695, 43347, 244228, 1376077, 7753553, 43687910, 246163281, 1387029593, 7815349472, 44036333771, 248126951851, 1398095180302, 7877701886559, 44387669863035, 250106600625676, 1409249728938893
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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) = 6*a(n-1) + 2*a(n-2) - 22*a(n-3) - 6*a(n-4) + 6*a(n-5) + a(n-6).
Empirical g.f.: x*(43 - 15*x - 178*x^2 - 41*x^3 + 49*x^4 + 8*x^5) / (1 - 6*x - 2*x^2 + 22*x^3 + 6*x^4 - 6*x^5 - x^6). - Colin Barker, Dec 25 2018
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EXAMPLE
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Some solutions for n=4:
..1..1..0....1..0..0....1..0..0....0..0..1....1..1..1....1..1..0....1..0..1
..0..1..0....0..0..0....0..0..0....0..0..1....0..1..0....0..1..1....1..0..1
..1..1..0....1..1..0....1..1..1....1..0..0....0..0..0....0..0..1....0..0..1
..0..1..0....0..1..0....0..0..1....1..1..0....0..0..0....1..1..1....0..0..0
..0..1..0....0..1..0....1..1..1....0..1..1....0..1..1....0..0..1....0..1..1
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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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