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A140902
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Number of 4 X 5 matrices with elements in 0..n with each row and each column in nondecreasing order. 4,5,n can be permuted, see formula.
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1
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1, 126, 5292, 116424, 1646568, 16818516, 133613766, 868489479, 4789851066, 23029990984, 98561919456, 381644355456, 1354627767168, 4454641311264, 13691471089032, 39620253756006, 108618373687131, 283595960194470, 708397594804900, 1699573176873000
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OFFSET
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0,2
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LINKS
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FORMULA
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(empirical) set p,q,r to n,5,4 (in any order) in s=p+q+r-1; a(n) = product {i in 0..r-1} (binomial(s,p+i)*i!/(s-i)^(r-i-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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