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A269507
Number of 3Xn arrays containing n copies of 0..3-1 avoiding the pattern down-up in every row and column.
1
4, 54, 420, 3088, 25226, 239994, 2338286, 23240168, 232006814, 2352889414, 24069853302, 248560741574, 2582277394354, 26997628173380, 283652378887212, 2994183763030920, 31727834772912212, 337396544704648686
OFFSET
1,1
COMMENTS
Row 3 of A269505.
LINKS
EXAMPLE
Some solutions for n=4
..1..1..2..0. .1..0..0..1. .0..0..2..1. .0..0..2..2. .0..1..2..1
..1..1..2..2. .2..1..1..2. .0..2..2..1. .1..2..1..1. .0..2..2..1
..0..0..0..2. .0..2..2..0. .2..1..1..0. .1..2..0..0. .2..0..0..1
CROSSREFS
Cf. A269505.
Sequence in context: A156469 A001545 A208954 * A302942 A292305 A073863
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 28 2016
STATUS
approved