login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

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
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 23 2012
STATUS
approved