OFFSET
1,1
COMMENTS
Column 3 of A208567.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 22*a(n-1) - 110*a(n-2) + 180*a(n-3) - 60*a(n-4) for n>5.
Empirical g.f.: x*(5 - 42*x + 113*x^2 - 110*x^3 + 30*x^4) / (1 - 22*x + 110*x^2 - 180*x^3 + 60*x^4). - Colin Barker, Jul 05 2018
EXAMPLE
Some solutions for n=4:
..0..0..0....0..0..1....0..0..0....0..0..0....0..0..1....0..0..1....0..1..2
..1..1..1....2..1..2....0..1..1....0..1..2....2..1..2....2..1..0....1..2..0
..1..0..0....2..0..0....1..2..0....2..0..1....2..0..2....2..0..1....0..1..0
..1..2..2....0..2..1....1..2..1....0..1..0....2..0..1....2..0..2....2..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 28 2012
STATUS
approved