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A266995
Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its west, northeast or northwest neighbor modulo 3 and the upper left element equal to 0.
2
2, 2, 2, 2, 2, 5, 14, 44, 127, 325, 779, 1794, 3988, 8830, 19835, 45596, 108019, 262831, 649761, 1616713, 4017231, 9918784, 24298996, 59106476, 143053467, 345488183, 834978807, 2023884377, 4926308772, 12044390597, 29559301172, 72735281709
OFFSET
1,1
COMMENTS
Row 3 of A266994.
LINKS
EXAMPLE
Some solutions for n=7
..0..2..1..0..2..1..0....0..0..0..0..2..2..1....0..0..0..2..2..1..1
..1..0..2..1..0..2..1....0..0..2..2..2..1..1....0..2..2..2..1..1..0
..2..1..0..2..1..0..2....0..2..2..1..1..1..1....2..2..1..1..1..0..0
CROSSREFS
Cf. A266994.
Sequence in context: A115101 A241148 A172414 * A051887 A139516 A225953
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 08 2016
STATUS
approved