A140906 Number of 6 X 6 matrices with elements in 0..n with each row and each column in nondecreasing order. 6,6,n can be permuted, see formula.

1, 924, 226512, 24293412, 1447482465, 55197331332, 1478619421136, 29706808370096, 469699956117392, 6062460972064640, 65728947490132992, 612416828057104512, 4995284546047230864, 36217696550300209296, 236405501218419838800, 1404221840699607829900

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Formula

(empirical) set p,q,r to n,6,6 (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: A177304 A022053 A107517 * A179715 A351485 A362171

Adjacent sequences: A140903 A140904 A140905 * A140907 A140908 A140909

Keyword

nonn

Author

R. H. Hardin, Jul 05 2008

Status

approved