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A224393
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Number of 4Xn 0..3 arrays with diagonals and antidiagonals unimodal and rows nondecreasing
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1
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256, 10000, 86701, 497958, 2332222, 9331553, 32806574, 103452812, 297410156, 789731500, 1957606141, 4569537752, 10116846904, 21372349639, 43300242010, 84493906854, 159387825448, 291579791772, 518714491591, 899524090772
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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) = (3551/47900160)*n^12 + (17561/13305600)*n^11 + (410317/21772800)*n^10 + (127787/725760)*n^9 + (394837/290304)*n^8 + (4724393/1209600)*n^7 + (880093831/21772800)*n^6 - (673403/80640)*n^5 + (476636641/1088640)*n^4 + (58121267/907200)*n^3 - (1924453/415800)*n^2 - (1998055/2772)*n + 1906 for n>4
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EXAMPLE
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Some solutions for n=3
..0..0..1....0..1..2....3..3..3....0..3..3....0..0..3....2..2..2....1..1..3
..0..2..3....0..3..3....0..1..3....2..3..3....0..1..1....2..3..3....3..3..3
..2..2..2....2..3..3....0..0..1....2..3..3....1..1..2....0..2..3....1..3..3
..1..2..3....0..2..3....0..1..2....2..2..3....0..0..2....2..3..3....0..1..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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