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

1,4

Comments

Row 3 of A268142.

Links

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

Example

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

Crossrefs

Cf. A268142.

Sequence in context: A129792 A224664 A222692 * A093759 A066415 A143557

Adjacent sequences: A268140 A268141 A268142 * A268144 A268145 A268146

Keyword

nonn

Author

R. H. Hardin, Jan 27 2016

Status

approved