A140902 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.

1, 126, 5292, 116424, 1646568, 16818516, 133613766, 868489479, 4789851066, 23029990984, 98561919456, 381644355456, 1354627767168, 4454641311264, 13691471089032, 39620253756006, 108618373687131, 283595960194470, 708397594804900, 1699573176873000

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Formula

(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))

Crossrefs

Sequence in context: A286976 A186816 A292882 * A270512 A037963 A240929

Adjacent sequences: A140899 A140900 A140901 * A140903 A140904 A140905

Keyword

nonn

Author

R. H. Hardin, Jul 05 2008

Status

approved