A140904 Number of 4 X 6 matrices with elements in 0..n with each row and each column in nondecreasing order. 4,6,n can be permuted, see formula.

1, 210, 13860, 457380, 9343620, 133613766, 1447482465, 12544848030, 90474964580, 559299781040, 3031952379456, 14675134144320, 64344818940480, 258616676126160, 962206162645860, 3341308066756506, 10904939897954025, 33648885753232750, 98669664990682500

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Formula

(empirical) set p,q,r to n,6,4 (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: A323963 A023905 A035840 * A092711 A187308 A229754

Adjacent sequences: A140901 A140902 A140903 * A140905 A140906 A140907

Keyword

nonn

Author

R. H. Hardin, Jul 05 2008

Status

approved