OFFSET
1,1
COMMENTS
Row 3 of A207346.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + a(n-3) - 2*a(n-4) - a(n-5) - a(n-6) for n>7.
Empirical g.f.: 6*x*(1 + x)*(1 + 3*x - x^2 + 4*x^3 - x^4 + x^5) / ((1 - x - x^3)*(1 - x - x^2 - x^3)). - Colin Barker, Jun 22 2018
EXAMPLE
Some solutions for n=4:
..1..0..0..1....0..0..1..0....0..0..1..0....1..1..0..0....1..0..1..0
..1..0..1..0....0..1..0..0....1..0..0..1....1..1..1..1....0..0..1..0
..0..1..0..1....1..1..0..1....0..1..0..1....0..0..1..0....0..1..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 17 2012
STATUS
approved