A140912 - OEIS

A140912

Number of 3 X 8 matrices with elements in 0..n with each row and each column in nondecreasing order. 3,8,n can be permuted, see formula.

1, 165, 9075, 259545, 4723719, 61408347, 614083470, 4971151900, 33803832920, 198520691512, 1028698128744, 4783805983320, 20239179160200, 78777112731240, 284722993157196, 963033653325810, 3068489581675375, 9262468551496875, 26617409626933125

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

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

FORMULA

(empirical) set p,q,r to n,8,3 (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: A194483 A105944 A071576 * A132055 A273441 A046178

Adjacent sequences: A140909 A140910 A140911 * A140913 A140914 A140915

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 05 2008

STATUS

approved