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A223627
Number of 3Xn 0..1 arrays with row sums nondecreasing and column sums unimodal
1
4, 26, 147, 751, 3560, 15778, 67030, 274631, 1088767, 4218662, 16015929, 59653826, 219063215, 794078382, 2843032061, 10081383128, 35429305737, 123436612116, 427070556002, 1467917436855, 5013326271265, 17031672794426, 57571509067410
OFFSET
1,1
COMMENTS
Row 3 of A223625
LINKS
EXAMPLE
Some solutions for n=3
..0..1..0....0..0..1....0..1..0....1..0..0....0..0..1....0..0..0....0..0..1
..0..1..0....1..1..0....1..0..0....0..1..0....0..1..0....0..0..0....1..1..1
..1..0..0....1..1..1....1..0..0....0..0..1....0..0..1....0..0..1....1..1..1
CROSSREFS
Sequence in context: A229278 A180226 A325587 * A144068 A204062 A121767
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 24 2013
STATUS
approved