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A224407
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Number of n X 6 0..1 arrays with rows unimodal and antidiagonals nondecreasing.
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1
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22, 169, 879, 3902, 16420, 68282, 284254, 1187830, 4979464, 20913026, 87905004, 369597368, 1554028138, 6533901986, 27470619810, 115492192540, 485546657850, 2041301158120, 8581884687952, 36079321433650, 151682073514422
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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) = 7*a(n-1) -14*a(n-2) +9*a(n-3) +4*a(n-5) +16*a(n-6) for n>7.
Empirical g.f.: x*(22 + 15*x + 4*x^2 - 83*x^3 - 109*x^4 - 29*x^5 + 14*x^6) / (1 - 7*x + 14*x^2 - 9*x^3 - 4*x^5 - 16*x^6). - Colin Barker, Aug 30 2018
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EXAMPLE
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Some solutions for n=3:
..0..0..0..0..0..0....0..0..0..0..0..1....1..0..0..0..0..0....0..0..0..1..0..0
..0..0..0..0..1..0....0..0..0..1..1..1....0..1..1..1..0..0....0..0..1..1..0..0
..0..0..1..1..1..0....0..1..1..1..1..0....1..1..1..0..0..0....1..1..1..0..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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