OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-3) + 5*a(n-4) + 2*a(n-5) + 8*a(n-6) + 8*a(n-7) - 4*a(n-8) - 8*a(n-9) for n>10.
Empirical g.f.: 2*x*(24 + 52*x + 137*x^2 + 184*x^3 + 155*x^4 + 294*x^5 + 280*x^6 - 88*x^7 - 256*x^8 - 96*x^9) / (1 - 4*x^3 - 5*x^4 - 2*x^5 - 8*x^6 - 8*x^7 + 4*x^8 + 8*x^9). - Colin Barker, Dec 29 2018
EXAMPLE
Some solutions for n=4:
..0..0..0....0..0..0....0..0..1....0..0..0....1..0..0....0..0..0....0..0..1
..1..0..0....0..0..1....1..1..0....0..0..0....0..0..0....0..1..1....0..1..0
..0..0..1....0..0..0....0..0..0....1..0..0....0..1..0....0..0..0....0..0..0
..0..0..0....0..0..0....0..0..0....0..0..1....0..1..0....0..0..0....0..0..0
..0..0..0....1..0..0....0..1..0....0..0..0....0..0..0....1..1..0....1..1..0
..1..0..0....1..0..0....0..0..1....0..1..0....1..0..0....0..0..1....1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 22 2015
STATUS
approved