OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + a(n-2) + a(n-3) + 5*a(n-4) - 3*a(n-5) - 5*a(n-6) + 3*a(n-7) - 4*a(n-8) + 2*a(n-9) for n>11.
Empirical g.f.: 2*x*(24 + 14*x + 24*x^2 + 21*x^3 - 99*x^4 - 38*x^5 + 48*x^6 - 45*x^7 + 47*x^8 - 6*x^9 - 2*x^10) / ((1 - x)*(1 - x^2 - 2*x^3 - 7*x^4 - 4*x^5 + x^6 - 2*x^7 + 2*x^8)). - Colin Barker, Dec 31 2018
EXAMPLE
Some solutions for n=7:
..0..0..1....0..0..0....1..0..1....0..0..0....1..0..0....0..0..0....1..0..0
..0..0..0....0..1..0....0..0..0....0..1..0....1..1..0....1..0..0....0..0..0
..0..0..1....1..0..0....0..0..0....0..0..1....1..0..0....0..0..0....1..0..0
..0..0..0....0..0..0....1..0..0....0..0..0....0..0..0....0..0..0....0..0..0
..0..0..0....0..0..0....0..1..0....0..0..0....0..0..0....0..0..1....0..0..0
..0..1..0....0..0..1....0..0..0....0..0..1....0..0..1....0..0..0....0..0..1
..0..0..1....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..1..1
..0..0..0....0..0..1....1..0..0....0..0..0....0..0..0....0..1..0....0..0..1
..0..0..0....0..1..0....0..1..0....0..1..0....0..0..1....0..1..0....0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 28 2015
STATUS
approved