OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - a(n-3) + 3*a(n-4) - 2*a(n-5).
Empirical g.f.: x*(2 - 2*x + x^3 - 2*x^4) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - x + x^2)). - Colin Barker, Dec 31 2018
EXAMPLE
Some solutions for n=4:
..0..0..0..0....1..0..0..1....0..0..0..0....1..0..0..1....0..0..0..0
..0..0..0..0....1..0..0..1....1..0..0..1....1..0..0..1....1..0..0..1
..0..0..0..0....1..0..0..1....1..0..0..1....1..0..0..1....0..0..0..0
..0..0..0..0....0..0..0..0....1..0..0..1....1..0..0..1....0..0..0..0
..0..0..0..0....1..0..0..1....1..0..0..1....1..0..0..1....1..0..0..1
..0..0..0..0....0..0..0..0....1..0..0..1....1..0..0..1....0..0..0..0
..0..0..0..0....1..0..0..1....1..0..0..1....0..0..0..0....0..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 18 2015
STATUS
approved