A206628 revision #6
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A206628
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Number of (n+1) X 2 0..2 arrays with every 2 X 3 or 3 X 2 subblock having no more than four equal edges, and new values 0..2 introduced in row major order.
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2
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14, 121, 1085, 9729, 87238, 782246, 7014246, 62895364, 563970356, 5057011236, 45345224920, 406601711384, 3645917557848, 32692225503376, 293144754758096, 2628571347438864, 23569882170595936, 211346496672826976
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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) = 8*a(n-1) + 8*a(n-2) + 6*a(n-3) for n>4.
Empirical g.f.: x*(14 + 9*x + 5*x^2 - 3*x^3) / (1 - 8*x - 8*x^2 - 6*x^3). - Colin Barker, Mar 04 2018
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EXAMPLE
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Some solutions for n=4:
..0..1....0..1....0..0....0..1....0..1....0..0....0..0....0..1....0..1....0..1
..0..2....0..0....1..1....2..0....2..0....0..0....0..1....1..1....0..2....0..2
..2..0....1..1....1..1....1..2....0..1....0..1....2..1....0..1....1..2....1..1
..0..2....1..0....1..0....2..0....2..2....0..1....2..0....2..2....2..1....1..2
..1..0....2..1....1..2....0..1....2..1....1..2....0..1....1..2....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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editing
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