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A221395
Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, with every occupancy equal to zero or two
1
4, 54, 631, 7678, 93398, 1137850, 13857444, 168717375, 2053766992, 24997337148, 304235229651, 3702632940296, 45061321786573, 548394286665966, 6673898631211550, 81220384265578677, 988438827804013263
OFFSET
1,1
COMMENTS
Column 4 of A221396
LINKS
EXAMPLE
Some solutions for n=3
..0..2..2..0....2..2..0..2....2..0..2..0....2..2..0..0....0..2..2..2
..0..2..2..0....2..0..2..2....2..2..0..2....2..2..2..2....2..0..0..0
..0..2..0..2....0..0..0..0....0..2..0..0....0..0..0..0....0..0..2..2
CROSSREFS
Sequence in context: A073863 A269480 A199022 * A357558 A241126 A089205
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 14 2013
STATUS
approved