A204624 Number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having unequal diagonal elements or unequal antidiagonal elements, and new values 0..2 introduced in row major order.

96, 2049, 43734, 933462, 19923888, 425257068, 9076721064, 193734264456, 4135079723136, 88259474206608, 1883817316421472, 40208348322379872, 858210220662456576, 18317707978060726464, 390974632428061590144

Offset: 1

Author

R. H. Hardin, Jan 17 2012

Keywords

• nonn

Comments

Column 2 of A204630.

Examples

			Some solutions for n=3:
..0..0..0....0..0..1....0..0..1....0..1..2....0..0..1....0..0..1....0..1..0
..0..1..1....2..0..2....2..0..2....1..2..2....2..0..0....2..0..2....2..1..2
..1..2..0....0..0..2....2..2..1....0..2..1....2..0..1....1..0..2....2..1..1
..1..2..1....2..0..2....0..2..1....1..1..0....2..2..2....1..2..1....0..1..2
		

Links

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

Crossrefs

Cf. A204630.

Formula

Empirical: a(n) = 22*a(n-1) -14*a(n-2).

Conjectures from Colin Barker, Jun 07 2018: (Start)

G.f.: 3*x*(32 - 21*x) / (1 - 22*x + 14*x^2).

a(n) = (3*(11+sqrt(107))^n*(31+3*sqrt(107)) + (11-sqrt(107))^n*(-93+9*sqrt(107))) / (4*sqrt(107)).

(End)