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A224154
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Number of nX4 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing
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1
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11, 56, 187, 574, 1783, 5657, 18408, 61140, 205390, 694018, 2350061, 7961090, 26964678, 91303265, 309082754, 1046163241, 3540718751, 11983122960, 40555030532, 137252283821, 464510611475, 1572073476421, 5320479934245
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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) = 5*a(n-1) -5*a(n-2) -2*a(n-3) -3*a(n-4) +18*a(n-5) -18*a(n-6) +27*a(n-7) -3*a(n-8) -4*a(n-9) -8*a(n-11) -6*a(n-12) -6*a(n-13) for n>14
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EXAMPLE
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Some solutions for n=3
..0..0..0..0....1..1..0..0....1..1..1..0....1..1..1..1....0..1..0..0
..1..0..0..0....1..1..0..0....1..1..0..0....1..1..1..1....1..1..1..0
..1..1..1..1....1..1..1..0....1..1..1..0....1..1..1..0....1..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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