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A221611
Number of 3Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, without move-in move-out left turns
1
0, 4, 54, 811, 11344, 160999, 2286878, 32522604, 462463456, 6575844726, 93499812718, 1329429617150, 18902457108916, 268763744810865, 3821403968991766, 54334437063306418, 772551392056456162
OFFSET
1,2
COMMENTS
Row 3 of A221609
LINKS
EXAMPLE
Some solutions for n=3
..1..2..0....0..3..1....0..3..1....0..2..1....0..2..1....1..1..0....1..2..0
..0..3..1....1..1..0....0..1..0....0..2..2....0..3..1....0..3..1....0..2..1
..0..1..1....1..2..0....2..2..0....0..2..0....1..1..0....1..2..0....1..2..0
CROSSREFS
Sequence in context: A294041 A055774 A071248 * A303048 A304556 A127833
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 20 2013
STATUS
approved