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A208692
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Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 0 1 vertically.
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1
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21, 441, 1113, 11067, 41013, 301035, 1346961, 8556723, 42184905, 249260739, 1292345649, 7358809899, 39164938617, 218805732243, 1180444035057, 6530395532955, 35479909625769, 195286010577987, 1064871399311265
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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) = a(n-1) + 26*a(n-2) + 6*a(n-3) - 78*a(n-4).
Empirical g.f.: 21*x*(1 + 20*x + 6*x^2 - 78*x^3) / (1 - x - 26*x^2 - 6*x^3 + 78*x^4). - Colin Barker, Jul 05 2018
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EXAMPLE
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Some solutions for n=4:
..0..1..0..1....0..1..1..0....1..0..1..1....1..1..0..1....1..1..1..1
..1..1..0..0....1..1..1..1....1..1..1..1....0..1..0..1....0..1..0..0
..0..1..0..0....0..1..1..0....1..0..1..1....0..1..0..1....0..1..0..0
..0..1..1..0....0..1..0..0....1..0..1..0....0..1..0..1....0..1..1..1
..0..1..0..0....0..1..0..0....1..0..1..0....1..1..1..1....1..1..0..0
..1..1..0..1....0..1..0..0....1..1..1..0....0..1..0..0....0..1..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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