login
A202042
Number of zero-sum nX3 -1..1 arrays with every element unequal to at most two horizontal and vertical neighbors
1
7, 73, 415, 2921, 19541, 149149, 1067983, 8193025, 60897081, 469758219, 3566405667, 27631630057, 212463113105, 1652463728885, 12810745435213, 99982282638169, 779490730807285, 6102033983822007, 47767263490283739
OFFSET
1,1
COMMENTS
Column 3 of A202047
LINKS
EXAMPLE
Some solutions for n=5
..1.-1..0....1..0..0...-1.-1..1....1..1.-1...-1..1..0....1.-1.-1...-1..0..1
.-1.-1.-1....1..0..0...-1..1..1...-1.-1.-1....1..1.-1....0..0.-1....1..0..1
..1.-1.-1....0..0..0...-1..1..1....1..1..1....1..1.-1....0..0..0....1..0..0
..1..1..1...-1.-1.-1...-1..0..0....1.-1.-1...-1.-1.-1....0..0..0....0..0..0
..0..0..1....0..0..1....0..0..0....1.-1..0....0..0..1....1..1..0...-1.-1.-1
CROSSREFS
Sequence in context: A373685 A027017 A076106 * A294291 A318688 A117982
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 10 2011
STATUS
approved