A231420 Number of (1+1) X (n+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, 71, 514, 3838, 28486, 212060, 1578180, 11748804, 87465304, 651171800, 4847955288, 36093104816, 268714229264, 2000587354768, 14894452176096, 110889806477664, 825579209354848, 6146471657514944, 45760738536130624

Offset: 1

Author

R. H. Hardin, Nov 08 2013

Keywords

• nonn

Examples

			Some solutions for n=6:
..0..0..1..2..0..0..2....0..0..1..1..0..2..0....0..1..2..2..1..0..2
..1..2..0..2..2..0..1....1..1..2..2..1..1..1....0..1..0..1..1..2..2
		

Links

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

Crossrefs

Row 1 of A231419.

Formula

Empirical: a(n) = 8*a(n-1) + 4*a(n-2) - 58*a(n-3) - 24*a(n-4) + 40*a(n-5) - 16*a(n-6).

Empirical g.f.: x*(9 - x - 90*x^2 - 36*x^3 + 60*x^4 - 24*x^5) / (1 - 8*x - 4*x^2 + 58*x^3 + 24*x^4 - 40*x^5 + 16*x^6). - Colin Barker, Sep 28 2018