A231413 Number of (n+1) X (1+1) 0..2 arrays with no element equal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.

9, 50, 285, 1617, 9188, 52193, 296511, 1684466, 9569425, 54363701, 308839124, 1754508933, 9967330587, 56624207962, 321681006005, 1827463435305, 10381783646596, 58978707645369, 335056872107879, 1903451466275938

Offset: 1

Author

R. H. Hardin, Nov 08 2013

Keywords

• nonn

Comments

Column 1 of A231419.

Examples

			Some solutions for n=5:
..0..1....0..0....0..1....0..1....0..0....0..1....0..1....0..1....0..1....0..1
..0..2....1..2....0..2....0..2....1..2....0..1....1..2....0..1....0..2....2..1
..0..1....1..2....0..1....0..1....0..1....1..2....0..2....1..0....2..1....2..0
..2..1....1..0....2..1....1..0....2..0....1..0....2..1....2..2....0..1....1..0
..2..0....1..2....0..2....2..0....1..2....2..2....2..0....0..1....1..2....1..0
..0..1....0..0....0..2....2..0....0..1....1..1....2..1....0..1....1..2....2..0
		

Links

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

Crossrefs

Cf. A231419.

Formula

Empirical: a(n) = 6*a(n-1) - 11*a(n-3) + 4*a(n-4).

Empirical g.f.: x*(9 - 4*x - 15*x^2 + 6*x^3) / (1 - 6*x + 11*x^3 - 4*x^4). - Colin Barker, Feb 21 2018