OFFSET
1,1
COMMENTS
Column 2 of A202802.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) + a(n-2) + 4*a(n-3).
Empirical g.f.: 2*x*(1 + 2*x + 2*x^2) / (1 - 3*x - x^2 - 4*x^3). - Colin Barker, Feb 20 2018
EXAMPLE
Some solutions for n=5:
..0..1....0..0....0..1....1..0....0..0....1..0....1..1....0..1....0..1....1..0
..0..1....1..0....1..1....1..0....0..0....1..0....1..1....1..1....1..1....1..1
..1..1....1..1....1..1....1..1....0..1....0..0....1..0....0..0....1..0....0..1
..1..1....0..1....1..0....1..0....0..1....0..1....0..1....1..0....0..0....1..0
..1..0....1..1....1..0....1..0....0..0....0..1....1..1....1..1....0..0....1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 24 2011
STATUS
approved