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A201884
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Number of zero-sum nX1 -2..2 arrays with every element equal to at least one horizontal or vertical neighbor
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1
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0, 1, 1, 5, 1, 23, 25, 97, 155, 553, 893, 2945, 5721, 16499, 34509, 96903, 211929, 571639, 1310827, 3446631, 8106415, 21036009, 50484447, 129556711, 315618625, 804915729, 1980809241, 5032086931, 12478845269, 31624865741, 78861551727
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OFFSET
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1,4
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COMMENTS
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LINKS
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EXAMPLE
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Some solutions for n=8
..2...-2....1...-2....0....0....1....1....2....1...-1....0....0...-2...-1....0
..2...-2....1...-2....0....0....1....1....2....1...-1....0....0...-2...-1....0
..0....0....0....2...-2....1....0...-1...-1...-1...-1...-1....0....2...-2....1
..0....0....0....2...-2....1....0...-1...-1...-1...-1...-1....0....2...-2....1
.-2....1...-2...-2....1...-2....0...-1....1....2....2...-1....1....0....1....1
.-2....1...-2...-2....1...-2....0...-1....1....2....2....1....1....0....1....1
..0....1....1....2....1....1...-1....1...-2...-2....0....1...-1....0....2...-2
..0....1....1....2....1....1...-1....1...-2...-2....0....1...-1....0....2...-2
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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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