A268143 Number of 3 X n arrays containing n copies of 0..3-1 with every element equal to at least one diagonal or antidiagonal neighbor and the top left element equal to 0.

0, 0, 0, 8, 32, 238, 1488, 9778, 91628, 685364, 5183732, 43292440, 341958992, 2698310688, 22015262376, 177423576662, 1428012268840, 11630157575168, 94604167006872, 769682941957332, 6291338814803772, 51481101154395306

Offset: 1

Author

R. H. Hardin, Jan 27 2016

Keywords

• nonn

Comments

Row 3 of A268142.

Examples

			Some solutions for n=4
..0..1..0..2....0..1..2..1....0..2..1..2....0..1..1..2....0..2..0..1
..1..0..2..1....2..0..1..2....1..0..2..1....1..0..2..1....2..0..1..2
..0..2..1..2....0..2..0..1....0..1..0..2....0..2..0..2....0..1..2..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..52

Crossrefs

Cf. A268142.