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A239188
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Number of n X 2 0..4 arrays with no element equal to the sum of elements to its left or the sum of elements above it, modulo 5.
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1
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12, 120, 1276, 13128, 136684, 1416192, 14700364, 152485288, 1582134540, 16414034784, 170295680876, 1766793480968, 18330328103340, 190175177307584, 1973048416742796, 20470174034391656, 212375968504319052
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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) + 50*a(n-2) - 26*a(n-3) - 253*a(n-4) + 240*a(n-5) + 416*a(n-6) - 624*a(n-7).
Empirical g.f.: 4*x*(3 + 12*x - 11*x^2 - 54*x^3 + 68*x^4 + 86*x^5 - 156*x^6) / (1 - 6*x - 50*x^2 + 26*x^3 + 253*x^4 - 240*x^5 - 416*x^6 + 624*x^7). - Colin Barker, Oct 25 2018
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EXAMPLE
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Some solutions for n=5:
..4..1....4..3....2..3....1..3....2..3....3..2....2..1....3..2....1..4....1..2
..1..0....1..0....3..0....3..0....3..1....1..0....1..3....1..4....4..3....4..1
..3..4....4..0....2..0....3..0....1..0....2..1....1..2....1..3....4..1....1..0
..2..3....2..4....1..2....4..0....2..1....2..1....2..0....4..1....3..1....3..1
..2..4....2..0....2..4....3..4....2..1....1..2....2..4....1..3....3..1....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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