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A201885
Number of zero-sum nX2 -2..2 arrays with every element equal to at least one horizontal or vertical neighbor
1
1, 9, 63, 413, 3293, 25123, 196811, 1610765, 13183301, 109772649, 924269015, 7845330131, 67157103399, 578601709251, 5012862231269, 43640547493913, 381459159995789, 3345900096556721, 29435197443234979, 259612374333413841
OFFSET
1,2
COMMENTS
Column 2 of A201888
LINKS
EXAMPLE
Some solutions for n=6
.-1.-1...-1.-1....0..0...-1.-1...-1.-1....1..1...-1..2....0..0....0..2....1..1
..1.-2...-1..0....2..0....0..0....0..0....1..0...-1..2...-1..2....0..2...-1.-1
..1.-2...-1..0....2..0...-1..0....0..0....0..0....1..1...-1..2...-1.-1....0.-1
..0..0....2..2...-1.-1...-1..2....0..0...-1..0...-2.-2....0..0...-1..0....0..1
..0..0...-2.-2....0..0....0..2....2.-1...-1..0....2.-2....0.-1...-1..0....1..1
..2..2....2..2...-1.-1....0..0....2.-1...-1..0....2.-2....0.-1....0..0...-1.-1
CROSSREFS
Sequence in context: A016137 A230547 A339786 * A225964 A037508 A037691
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 06 2011
STATUS
approved