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A188829
Number of 7 X n binary arrays without the pattern 0 1 diagonally or antidiagonally.
1
128, 64, 224, 784, 2800, 10000, 36000, 129600, 468000, 1690000, 6110000, 22090000, 79900000, 289000000, 1045500000, 3782250000, 13683750000, 49506250000, 179112500000, 648025000000, 2344562500000, 8482656250000, 30690468750000
OFFSET
1,1
COMMENTS
Row 7 of A188824.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) - 25*a(n-3) + 25*a(n-4) for n>5.
Empirical g.f.: 16*x*(8 - 36*x - 6*x^2 + 179*x^3 - 170*x^4) / ((1 - 5*x + 5*x^2)*(1 - 5*x^2)). - Colin Barker, Apr 30 2018
EXAMPLE
Some solutions for 7 X 3:
..1..1..1....0..1..1....1..1..1....1..1..1....1..1..1....1..1..1....1..1..1
..0..1..1....1..0..1....1..1..1....1..0..0....1..1..1....1..1..1....1..1..1
..1..0..1....0..0..0....1..1..1....0..0..0....1..1..1....1..1..1....1..1..0
..0..1..0....0..0..0....1..1..1....0..0..0....1..1..1....1..1..0....1..0..1
..1..0..1....0..0..0....1..1..1....0..0..0....0..1..0....1..0..1....0..1..0
..0..1..0....0..0..0....0..1..0....0..0..0....1..0..0....0..0..0....1..0..1
..1..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..0..0....0..0..0
CROSSREFS
Cf. A188824.
Sequence in context: A336774 A252487 A160638 * A336776 A172532 A173779
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 11 2011
STATUS
approved