A232017 Number of n X 2 0..2 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.

3, 22, 121, 704, 4059, 23422, 135166, 779977, 4500958, 25973244, 149881402, 864906711, 4991036946, 28801314179, 166201073269, 959081123649, 5534480515641, 31937313562863, 184297694197368, 1063509616098391

Offset: 1

Author

R. H. Hardin, Nov 17 2013

Keywords

• nonn

Examples

			Some solutions for n=7:
..1..1....2..0....1..1....1..1....0..0....0..0....2..0....2..0....1..1....1..0
..1..0....0..0....0..0....0..0....1..0....0..0....0..1....0..0....1..2....0..1
..0..1....0..1....2..1....1..2....0..0....1..1....2..2....1..2....0..0....1..1
..0..0....2..0....0..0....1..1....1..2....2..2....0..0....1..1....1..1....2..0
..0..1....0..0....0..0....0..0....2..2....2..2....1..1....2..1....2..1....0..1
..2..0....1..1....0..2....0..0....2..1....1..0....1..0....0..0....1..1....0..0
..0..1....1..1....2..2....2..2....1..1....0..2....0..2....1..1....1..1....2..2
		

Links

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

Crossrefs

Column 2 of A232023.

Formula

Empirical: a(n) = 3*a(n-1) + 13*a(n-2) + 16*a(n-3) + 7*a(n-4) + a(n-5).

Empirical g.f.: x*(1 + x)*(3 + x)*(1 + 3*x + x^2) / (1 - 3*x - 13*x^2 - 16*x^3 - 7*x^4 - x^5). - Colin Barker, Oct 01 2018