OFFSET
1,1
COMMENTS
Column 8 of A186568
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..163
FORMULA
Empirical: a(n)=2*a(n-1)-a(n-2)+2*a(n-3)-4*a(n-4)+2*a(n-5)+2*a(n-6)-2*a(n-7) for n>16
EXAMPLE
Some solutions for 4X10
..0..0..2..0..0..0..0..0..0..2....1..0..0..1..0..0..2..0..0..1
..0..0..0..2..0..0..0..0..0..1....0..1..0..0..1..0..0..2..0..0
..0..0..0..0..2..0..0..0..0..0....0..0..1..0..0..1..0..0..2..0
..0..0..0..0..0..2..0..0..0..0....2..0..0..1..0..0..1..0..0..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 23 2011
STATUS
approved