OFFSET
1,1
COMMENTS
Column 5 of A209382.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 16*a(n-2) - 68*a(n-4) + 80*a(n-6).
Empirical g.f.: 2*x*(32 + 85*x - 352*x^2 - 822*x^3 + 704*x^4 + 1496*x^5) / ((1 - 2*x)*(1 + 2*x)*(1 - 2*x^2)*(1 - 10*x^2)). - Colin Barker, Jul 09 2018
EXAMPLE
Some solutions for n=4:
..2..2..0..1..0..0....0..2..0..0..0..2....1..2..2..2..2..2....2..1..2..2..0..1
..0..1..0..2..2..1....1..2..1..2..1..2....0..0..1..0..1..0....2..0..0..1..0..2
..2..2..0..1..0..0....0..2..0..2..0..2....1..2..2..0..2..0....2..1..2..2..0..1
..0..1..0..2..2..1....0..1..0..1..0..1....0..0..1..0..1..0....2..0..0..1..0..2
..0..2..0..1..0..0....0..2..0..2..2..2....1..2..2..2..2..2....2..1..2..2..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 07 2012
STATUS
approved