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A209738
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Number of n X 2 0..5 arrays with every 2 X 2 subblock containing exactly one value repeat, and new values 0..5 introduced in row major order.
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1
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2, 6, 57, 700, 10594, 183240, 3412100, 65953664, 1298076552, 25767620512, 513555943312, 10254450363264, 204934235829536, 4097247120151424, 81931587030997056, 1638507658307430400, 32769000295781617792
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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) = 32*a(n-1) - 258*a(n-2) + 296*a(n-3) + 1256*a(n-4) + 480*a(n-5) for n>6.
Empirical g.f.: x*(2 - 58*x + 381*x^2 - 168*x^3 - 1388*x^4 - 536*x^5) / ((1 - 20*x)*(1 - 4*x - 2*x^2)*(1 - 8*x - 12*x^2)). - Colin Barker, Jul 12 2018
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EXAMPLE
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Some solutions for n=5:
..0..0....0..0....0..0....0..1....0..0....0..0....0..0....0..1....0..1....0..0
..1..2....1..2....1..2....0..2....1..2....1..2....1..2....2..0....1..2....1..2
..0..0....0..0....2..0....0..3....1..0....0..0....2..0....0..3....0..0....1..3
..1..2....3..1....3..0....0..1....0..2....2..3....2..1....2..2....1..2....2..1
..1..3....4..1....0..4....0..2....0..1....2..4....2..0....0..1....1..0....3..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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