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A140919
Number of 4 X 9 matrices with elements in 0..n with each row and each column in nondecreasing order. 4,9,n can be permuted, see formula.
0
1, 715, 143143, 13026013, 677352676, 23029990984, 559299781040, 10323075958624, 151561524301616, 1832516612010448, 18748054569029968, 165848175033726640, 1291064254877933536, 8973605947365856720, 56367818871058637800, 323286019995777481500
OFFSET
0,2
FORMULA
(empirical) set p,q,r to n,9,4 (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: A222912 A266107 A030537 * A208352 A223061 A208863
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 05 2008
STATUS
approved