A188829 Number of 7 X n binary arrays without the pattern 0 1 diagonally or antidiagonally.

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

R. H. Hardin, Table of n, a(n) for n = 1..200

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

Adjacent sequences: A188826 A188827 A188828 * A188830 A188831 A188832

Keyword

nonn

Author

R. H. Hardin, Apr 11 2011

Status

approved