OFFSET
1,1
COMMENTS
Column 2 of A208796.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + 16*a(n-2) + 10*a(n-3) - 4*a(n-4).
Empirical g.f.: 2*x*(1 + x)*(3 + 6*x - 4*x^2) / (1 - 2*x - 16*x^2 - 10*x^3 + 4*x^4). - Colin Barker, Jul 06 2018
EXAMPLE
Some solutions for n=4:
..1..2....0..2....2..1....0..1....0..2....2..0....0..2....2..1....2..0....0..1
..2..0....1..2....0..2....2..2....2..2....1..2....1..2....0..2....0..1....2..2
..1..2....2..0....2..2....0..0....0..0....0..2....2..0....1..2....2..2....0..2
..2..2....0..1....1..2....1..1....2..1....2..0....1..0....2..1....0..2....1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 01 2012
STATUS
approved