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A239334
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Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it, modulo 4
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1
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5, 31, 172, 926, 5078, 27861, 152260, 832207, 4550810, 24881731, 136029644, 743697760, 4065948624, 22229220072, 121530709245, 664428372582, 3632538661095, 19859679158791, 108576093277449, 593603153333233
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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) = 9*a(n-1) -28*a(n-2) +74*a(n-3) -181*a(n-4) +236*a(n-5) -261*a(n-6) +234*a(n-7) +200*a(n-8) -279*a(n-9) +104*a(n-10) -268*a(n-11) -36*a(n-12) +156*a(n-13) +104*a(n-14) -32*a(n-15) -16*a(n-16)
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EXAMPLE
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Some solutions for n=5
..2..0....2..0....2..0....2..1....2..2....0..2....0..2....2..1....2..2....2..1
..3..2....2..1....3..1....2..1....0..3....0..2....0..0....2..2....0..2....2..2
..3..3....0..2....3..2....0..2....3..1....2..0....0..2....2..0....2..1....2..1
..2..2....0..3....2..0....0..0....3..3....0..2....2..0....3..1....0..3....3..1
..3..1....0..0....0..3....0..0....2..1....0..0....3..1....2..0....0..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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