OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-2) + 2*a(n-3) + 6*a(n-4) + 2*a(n-5) - a(n-6) + 2*a(n-7) - a(n-8) for n>9.
Empirical g.f.: x*(32 + 49*x + 72*x^2 + 88*x^3 - 18*x^4 - 22*x^5 + 26*x^6 - 29*x^7 + 6*x^8) / (1 - x^2 - 2*x^3 - 6*x^4 - 2*x^5 + x^6 - 2*x^7 + x^8). - Colin Barker, Dec 26 2018
EXAMPLE
Some solutions for n=4:
..0..0..1....0..1..0....0..1..0....0..0..1....0..0..0....0..0..0....1..0..1
..0..1..0....0..0..1....0..0..1....0..1..0....0..0..0....0..0..0....0..1..0
..0..0..1....0..0..0....0..0..0....0..0..1....1..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....0..0..0
..0..0..0....0..1..0....0..0..1....0..0..0....1..0..0....0..0..0....0..0..1
..0..0..1....0..0..1....0..1..0....0..1..0....0..1..0....1..0..1....0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 04 2015
STATUS
approved