A140921 Number of 6 X 9 matrices with elements in 0..n with each row and each column in nondecreasing order. 6,9,n can be permuted, see formula.

1, 5005, 5725720, 2530768240, 559299781040, 72261531710368, 6062460972064640, 356031798904887040, 15480536486999030720, 520384188062967417280

Offset

0,2

Links

Table of n, a(n) for n=0..9.

Formula

(empirical) set p,q,r to n,9,6 (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: A249081 A154059 A138637 * A295459 A238926 A209908

Adjacent sequences: A140918 A140919 A140920 * A140922 A140923 A140924

Keyword

nonn

Author

R. H. Hardin, Jul 05 2008

Status

approved