A267619 Number of 3 X n arrays containing n copies of 0..3-1 with every element equal to at least one horizontal or antidiagonal neighbor and the top left element equal to 0.

0, 2, 8, 42, 576, 5492, 68958, 814418, 9982880, 122186774, 1509756240, 18739734568, 233756282022, 2928054874344, 36812296612552, 464358008157458, 5874864170778700, 74526122250575078, 947703833383753558

Offset

1,2

Comments

Row 3 of A267617.

Links

R. H. Hardin, Table of n, a(n) for n = 1..43

Example

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

Crossrefs

Cf. A267617.

Sequence in context: A295199 A191479 A197935 * A012917 A050637 A349145

Adjacent sequences: A267616 A267617 A267618 * A267620 A267621 A267622

Keyword

nonn

Author

R. H. Hardin, Jan 18 2016

Status

approved