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A221726
Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with every occupancy equal to zero or two
1
0, 16, 0, 464, 0, 13948, 0, 420736, 0, 12695288, 0, 383074904, 0, 11559126552, 0, 348791805904, 0, 10524646286488, 0, 317576778411352, 0, 9582745781519416, 0, 289155325092787296, 0, 8725140362031620984, 0, 263277441988312544616, 0
OFFSET
1,2
COMMENTS
Column 3 of A221728
LINKS
FORMULA
Empirical: a(n) = 44*a(n-2) -462*a(n-4) +1400*a(n-6) -1417*a(n-8) -448*a(n-10) -280*a(n-12) +100*a(n-14)
EXAMPLE
Some solutions for n=4
..0..0..2....0..2..2....0..2..0....2..2..0....2..2..0....2..0..0....0..2..2
..2..2..0....2..0..0....2..2..2....2..0..0....0..2..2....0..2..2....0..2..0
..0..2..2....0..2..0....0..2..0....0..2..0....0..2..0....2..0..0....2..0..0
..2..0..0....2..0..2....0..0..2....0..2..2....0..0..2....2..2..0....2..2..0
CROSSREFS
Sequence in context: A169764 A002607 A221404 * A221729 A219950 A221271
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 22 2013
STATUS
approved