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A223865
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Number of 2Xn 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing
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4
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10, 100, 684, 3526, 14751, 52591, 165212, 468292, 1218812, 2951732, 6721028, 14507390, 29883426, 59065484, 112531519, 207449471, 371243434, 646728936, 1099377792, 1827431562, 2975775445, 4754716769, 7465089922, 11531438986
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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) = (1/19160064)*n^12 + (1/456192)*n^11 + (2287/43545600)*n^10 + (215/290304)*n^9 + (3991/580608)*n^8 + (2369/53760)*n^7 + (8836141/43545600)*n^6 + (136571/207360)*n^5 + (654599/435456)*n^4 + (865283/362880)*n^3 + (289699/103950)*n^2 + (39143/27720)*n + 1
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EXAMPLE
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Some solutions for n=3
..1..3..1....1..1..0....0..2..2....0..2..0....1..2..3....2..3..2....0..2..3
..2..3..1....1..3..1....0..3..2....1..3..2....3..3..3....2..3..3....1..2..3
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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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