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A201887
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Number of zero-sum nX4 -2..2 arrays with every element equal to at least one horizontal or vertical neighbor
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0
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OFFSET
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1,1
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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..2.-2..1....2..0.-2.-2....1..1.-1.-1....2.-1.-2.-2....2.-1.-1..2
.-1..0.-2..1....2..0..1..1....1.-2..2.-1....2.-1..1.-2....2.-1.-1..2
.-1..0..0..0...-1.-1..0..0...-2.-2..2..2....2..2..1.-2...-1.-1.-1.-1
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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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