OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + 5*a(n-2) - a(n-4).
Empirical g.f.: 3*x*(1 + 4*x - x^3) / (1 - 2*x - 5*x^2 + x^4). - Colin Barker, Oct 24 2018
EXAMPLE
Some solutions for n=5:
..0..1..1..0..1....0..1..0..1..0....0..1..0..1..0....0..1..0..0..1
..1..0..0..1..0....1..0..1..0..1....1..0..1..0..1....1..0..1..1..0
..1..0..1..0..1....0..1..0..0..1....0..1..0..1..0....0..1..0..1..0
..0..1..1..0..1....0..1..0..1..0....1..0..1..0..1....0..1..1..0..1
..1..0..0..1..0....1..0..1..0..1....0..1..0..1..0....1..0..1..1..0
..0..1..0..0..1....1..0..0..1..0....1..0..0..1..0....1..0..0..1..0
..1..0..1..1..0....0..1..1..0..1....0..1..1..0..1....0..1..1..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 02 2014
STATUS
approved