A267223 Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its west, northeast or southeast neighbor modulo 3 and the upper left element equal to 0.

2, 3, 8, 17, 34, 68, 164, 385, 826, 1848, 4450, 10544, 24056, 56108, 135672, 324720, 762864, 1818110, 4413518, 10641004, 25427616, 61338160, 149415144, 362365684, 875207554, 2127235158, 5197934580, 12666448776, 30813494386, 75278796468

Offset

1,1

Comments

Row 3 of A267222.

Links

R. H. Hardin, Table of n, a(n) for n = 1..154

Example

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

Crossrefs

Cf. A267222.

Sequence in context: A210701 A158921 A064954 * A292401 A132333 A182889

Adjacent sequences: A267220 A267221 A267222 * A267224 A267225 A267226

Keyword

nonn

Author

R. H. Hardin, Jan 12 2016

Status

approved