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A266887
Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north, northeast or northwest neighbor modulo 3 and the upper left element equal to 0.
2
1, 1, 1, 1, 1, 7, 41, 209, 999, 4603, 20763, 92601, 410279, 1811327, 7982401, 35151819, 154779159, 681698115, 3003887511, 13244742603, 58438985851, 258033686801, 1140171589651, 5041775026879, 22310625017943, 98798039343423
OFFSET
1,6
COMMENTS
Row 3 of A266886.
LINKS
EXAMPLE
Some solutions for n=7
..0..0..1..1..2..2..2....0..0..2..2..1..1..0....0..0..0..2..2..2..1
..2..0..0..1..1..1..2....2..2..2..1..1..0..0....0..0..2..2..1..1..1
..2..2..0..0..0..1..1....2..1..1..1..0..0..2....0..2..2..1..1..0..1
CROSSREFS
Cf. A266886.
Sequence in context: A366996 A238991 A084779 * A237664 A168584 A191010
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2016
STATUS
approved