OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) - 5*a(n-2) + a(n-3) + 3*a(n-4) - 4*a(n-5) + 2*a(n-6) + 2*a(n-7) - 3*a(n-8) + a(n-9) for n>11.
Empirical g.f.: x*(44 - 64*x + 68*x^2 - 16*x^3 - 43*x^4 + 18*x^5 + 12*x^6 - 12*x^7 - 2*x^8 + 6*x^9 - x^10) / ((1 - x)^3*(1 - x - x^2 - x^4 + x^6)). - Colin Barker, Dec 21 2018
EXAMPLE
Some solutions for n=4:
..0..0..1....1..1..1....0..0..0....0..0..1....0..0..1....0..0..0....1..0..0
..0..0..0....0..0..0....1..1..1....1..0..1....1..0..1....0..0..1....0..0..0
..1..0..1....1..1..1....0..0..0....1..0..1....1..0..1....0..0..1....1..1..0
..1..0..1....1..0..0....1..1..1....0..0..1....1..0..1....1..1..1....1..0..0
..0..0..1....1..1..1....1..0..1....1..1..1....0..1..1....1..1..0....1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 03 2015
STATUS
approved