OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-2) - 4*a(n-4) for n>6.
Empirical g.f.: 8*x*(20252 + 1067*x - 100635*x^2 - 4398*x^3 + 78883*x^4 + 1168*x^5) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)). - Colin Barker, Dec 14 2018
EXAMPLE
Some solutions for n=4:
..0..2..1..1..1..1....1..0..2..1..1..0....0..1..2..0..2..1....2..0..2..0..1..2
..1..1..2..0..1..0....0..1..1..2..0..1....0..2..1..1..0..2....2..2..1..1..0..2
..0..2..1..1..0..2....1..0..2..1..1..0....1..1..2..0..1..1....2..1..2..0..1..1
..1..1..2..0..1..1....0..1..1..2..0..1....0..2..1..1..0..2....0..2..1..1..0..2
..0..2..0..2..0..2....1..0..2..0..2..0....2..2..1..1..0..0....1..1..1..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 01 2015
STATUS
approved