A140921 - OEIS

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

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

KEYWORD

nonn

AUTHOR

STATUS

approved