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A202043
Number of zero-sum nX4 -1..1 arrays with every element unequal to at most two horizontal and vertical neighbors
1
19, 335, 2921, 31753, 359017, 4188917, 49553277, 594443301, 7206865523, 88120417529, 1084547246367, 13417760493253, 166705101517923, 2078489858665207, 25992085202674059, 325869090446388117
OFFSET
1,1
COMMENTS
Column 4 of A202047
LINKS
EXAMPLE
Some solutions for n=4
..1..1.-1.-1....1..1.-1..0...-1..1..1.-1....1.-1..1..1....0..1..1..0
.-1..1..1.-1....0.-1.-1..0....1..0..0.-1....1.-1..0..0....0..0..0..0
.-1..1..1.-1....0.-1..1..1....1..0..0.-1....1.-1..0..0....1.-1.-1.-1
.-1.-1..1..1...-1.-1..1..1....1..1.-1.-1...-1.-1..0..0....1.-1..0..0
CROSSREFS
Sequence in context: A121324 A093973 A345963 * A142549 A049629 A162805
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 10 2011
STATUS
approved