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A269506
Number of 2Xn arrays containing n copies of 0..2-1 avoiding the pattern down-up in every row and column.
2
2, 6, 14, 34, 92, 258, 722, 2022, 5706, 16232, 46442, 133418, 384550, 1111614, 3221582, 9357450, 27233148, 79394646, 231822854, 677835636, 1984435484, 5816254262, 17064740572, 50114985298, 147303657830, 433319078074
OFFSET
1,1
COMMENTS
Row 2 of A269505.
LINKS
EXAMPLE
Some solutions for n=4
..1..0..0..1. .0..0..1..1. .0..1..1..0. .0..0..1..1. .0..0..1..0
..0..1..1..0. .1..1..0..0. .1..1..0..0. .1..0..0..1. .0..1..1..1
CROSSREFS
Cf. A269505.
Sequence in context: A186523 A177790 A307068 * A292816 A105635 A178320
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 28 2016
STATUS
approved