OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) - 7*a(n-2) - 2*a(n-3) + 11*a(n-4) - 5*a(n-5) - 3*a(n-6) + 2*a(n-7).
Empirical g.f.: 2*x*(36 - 82*x + 3*x^2 + 129*x^3 - 73*x^4 - 43*x^5 + 32*x^6) / ((1 - x)^3*(1 + x)*(1 - 2*x)*(1 - x - x^2)). - Colin Barker, Nov 20 2018
EXAMPLE
Some solutions for n=4:
..1..1..0..0..0....0..1..0..0..0....0..1..0..0..1....0..0..0..1..0
..1..1..0..0..0....0..1..0..0..1....0..1..0..1..0....0..0..1..0..1
..1..1..0..0..1....0..1..0..0..1....1..0..1..0..1....0..0..1..0..1
..1..1..0..1..0....0..1..0..0..1....1..0..1..1..0....0..1..0..1..0
..1..1..0..1..0....0..1..1..1..0....1..0..1..1..0....0..1..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 27 2014
STATUS
approved