A208097 Number of 2 X n nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).

2, 4, 30, 377, 7239, 193228, 6752442, 296290708, 15835464207, 1007305486325, 74890158775564, 6413015600048526, 624933541074620780, 68603269124243415049, 8411144435499643711885, 1143251056778815843116186

Offset

1,1

Comments

Row 2 of A208096.

Links

R. H. Hardin, Table of n, a(n) for n = 1..19

Example

Some solutions for n=4:
..0..1..2..1....0..1..0..1....0..1..2..0....0..1..2..0....0..1..2..0
..3..1..4..5....0..1..0..2....0..1..3..1....0..1..2..0....3..1..2..4

Crossrefs

Sequence in context: A241542 A241540 A349265 * A132473 A053037 A018294

Adjacent sequences: A208094 A208095 A208096 * A208098 A208099 A208100

Keyword

nonn

Author

R. H. Hardin, Feb 23 2012

Status

approved