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A221872
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Number of nX4 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without consecutive moves in the same direction
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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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EXAMPLE
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Some solutions for n=3
..2..1..1..2....1..2..0..0....0..1..0..0....0..2..1..0....0..3..0..1
..1..1..0..1....0..3..0..3....2..3..1..1....0..3..1..1....0..4..3..0
..1..0..2..0....0..1..2..0....0..3..0..1....0..2..2..0....0..0..1..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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