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A224045
Number of nX3 0..3 arrays with rows and columns unimodal and antidiagonals nondecreasing
1
50, 984, 9731, 67585, 376734, 1801402, 7655477, 29502561, 104437965, 342818189, 1051490221, 3033475639, 8279003183, 21484969347, 53256520053, 126598758740, 289630093258, 639706047860, 1367894672765, 2838837855851, 5730717831654
OFFSET
1,1
COMMENTS
Column 3 of A224050
LINKS
FORMULA
Empirical: a(n) = (1/3629463552000)*n^18 + (7/403273728000)*n^17 + (667/951035904000)*n^16 + (3253/174356582400)*n^15 + (1895917/5230697472000)*n^14 + (1319281/249080832000)*n^13 + (509321/8211456000)*n^12 + (100859/174182400)*n^11 + (332201027/73156608000)*n^10 + (728354747/24385536000)*n^9 + (143150448337/804722688000)*n^8 + (121759327/136857600)*n^7 + (2559704983/808704000)*n^6 + (221471493559/31135104000)*n^5 + (346834471679/24216192000)*n^4 + (1741800289/181621440)*n^3 + (25437920323/1715313600)*n^2 + (1383692/69615)*n - 32 for n>1
EXAMPLE
Some solutions for n=3
..2..0..0....1..1..0....0..1..0....3..3..0....0..0..2....0..1..0....0..0..0
..3..1..0....1..1..3....3..3..0....3..1..1....0..2..0....1..2..2....0..1..0
..1..3..0....1..3..1....3..0..0....2..1..1....2..3..0....2..2..2....2..2..3
CROSSREFS
Sequence in context: A006360 A324217 A224059 * A224276 A224199 A112890
KEYWORD
nonn
AUTHOR
R. H. Hardin Apr 01 2013
STATUS
approved