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A223860
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Number of n X 4 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.
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1
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130, 3526, 41682, 315124, 1771012, 8008548, 30627033, 102479569, 307435001, 842078930, 2135465204, 5069027730, 11361881611, 24219158218, 49385314943, 96803565005, 183160193142, 335692581558, 597766839750, 1036890170376
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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 + (3551/1995840)*n^11 + (100307/4354560)*n^10 + (28081/145152)*n^9 + (1559477/1451520)*n^8 + (14951/3456)*n^7 + (54414629/4354560)*n^6 + (18845069/725760)*n^5 + (41975947/1088640)*n^4 + (7155619/181440)*n^3 + (694249/83160)*n^2 - (7351/990)*n - 11 for n>1.
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EXAMPLE
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Some solutions for n=3
..0..1..1..1....1..2..3..0....0..1..2..0....0..3..0..0....0..1..1..0
..3..2..2..1....1..2..3..3....1..2..3..1....2..3..0..0....0..2..1..0
..3..3..2..1....2..2..3..3....2..2..3..1....3..3..1..0....0..3..3..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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