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A221726
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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
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1
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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
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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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)
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EXAMPLE
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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
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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