A208558 Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 1 vertically.

16, 256, 784, 5776, 25600, 150544, 753424, 4129024, 21492496, 115175824, 607129600, 3230330896, 17097131536, 90759997696, 480986635024, 2551443960976, 13527095526400, 71739070491664, 380392441337104, 2017207032035584

Offset: 1

Author

R. H. Hardin, Feb 28 2012

Keywords

• nonn

Comments

Row 6 of A208555.

Examples

			Some solutions for n=4:
..0..1..0..1....0..1..1..1....1..0..1..0....1..0..1..0....0..1..0..0
..0..1..0..0....1..1..0..1....1..1..0..1....1..1..1..1....0..1..1..1
..0..1..0..1....0..1..0..1....1..0..1..0....1..0..1..0....0..1..0..0
..0..1..0..0....1..1..0..1....1..1..0..0....1..1..1..1....0..1..1..1
..0..1..0..1....0..1..0..1....1..0..1..0....1..0..1..0....0..1..0..0
..0..1..0..0....0..1..0..0....0..1..0..0....1..0..1..0....0..1..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A208555.

Formula

Empirical: a(n) = 4*a(n-1) +12*a(n-2) -27*a(n-3).

Empirical g.f.: 16*x*(1 + 12*x - 27*x^2) / ((1 + 3*x)*(1 - 7*x + 9*x^2)). - Colin Barker, Jul 04 2018