OFFSET
1,1
COMMENTS
Row 3 of A207453.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + 7*a(n-2) + 2*a(n-3) - 4*a(n-4).
Empirical g.f.: 6*x*(1 + 5*x + 2*x^2 - 4*x^3) / ((1 + x - x^2)*(1 - 2*x - 4*x^2)). - Colin Barker, Mar 05 2018
EXAMPLE
Some solutions for n=5:
..0..1..0..1..1....1..1..1..1..0....1..0..1..0..1....1..0..1..1..1
..1..1..0..1..0....1..0..1..1..1....1..0..1..0..1....0..1..1..1..1
..0..1..0..1..0....1..0..1..0..0....1..0..1..0..1....0..1..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 17 2012
STATUS
approved