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A201839
Number of zero-sum n X n -1..1 arrays with every element equal to at least one horizontal or vertical neighbor
0
0, 5, 125, 54773, 109797321, 1759241274383
OFFSET
1,2
COMMENTS
Diagonal of A201847
EXAMPLE
Some solutions for n=4
.-1..1..1..1...-1.-1..1..0...-1.-1..1..1...-1.-1.-1.-1...-1..1.-1.-1
.-1.-1.-1..1...-1..1..1..0....0.-1..0..0....0..1..0..0...-1..1..1.-1
..1.-1..1.-1....0..0.-1.-1....0..1..1..0....0..1.-1.-1....0..0..0..0
..1.-1..1.-1....1..1..0..0....0..1.-1.-1....1..1..1..1....0..1..1..0
CROSSREFS
Sequence in context: A109345 A194502 A229868 * A234609 A278080 A156956
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 06 2011
STATUS
approved