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A266474
Number of 7Xn binary arrays with rows and columns lexicographically nondecreasing and column sums nonincreasing.
1
8, 42, 303, 2574, 22128, 175180, 1231170, 7652503, 42460424, 212971589, 977395362, 4147719749, 16420984346, 61103700814, 215040758842, 719522481940, 2299243641848, 7043942786447, 20758083457211, 59015575393057
OFFSET
1,1
COMMENTS
Row 7 of A266470.
FORMULA
Empirical polynomial of degree 34 (see link above)
EXAMPLE
Some solutions for n=4
..0..0..0..1....0..0..1..1....0..0..1..1....0..0..0..1....0..1..1..1
..0..0..0..1....0..1..1..1....0..1..0..0....0..0..1..0....1..0..1..1
..0..1..1..0....1..0..0..0....1..0..0..1....0..1..0..0....1..0..1..1
..1..0..0..1....1..1..0..0....1..0..0..1....1..0..0..0....1..0..1..1
..1..1..1..0....1..1..0..1....1..1..0..0....1..1..1..1....1..1..0..0
..1..1..1..0....1..1..1..0....1..1..1..0....1..1..1..1....1..1..0..0
..1..1..1..1....1..1..1..1....1..1..1..0....1..1..1..1....1..1..0..0
CROSSREFS
Cf. A266470.
Sequence in context: A047772 A204565 A020068 * A238723 A316283 A236328
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 29 2015
STATUS
approved