OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + 3*a(n-2) - 4*a(n-3) - 6*a(n-4) + 4*a(n-6) + 6*a(n-7) + 3*a(n-8) - 2*a(n-9) - 3*a(n-10) - 2*a(n-11) - a(n-12).
Empirical g.f.: 2*x*(1 + x)*(5 + 32*x + 14*x^2 - 43*x^3 - 55*x^4 - 31*x^5 + x^6 + 28*x^7 + 24*x^8 + 10*x^9 + 3*x^10) / (1 - x - 2*x^2 + x^4 + x^5 + x^6)^2. - Colin Barker, Feb 17 2019
EXAMPLE
Some solutions for n=4:
..0..1..0..0..1..0. .0..0..1..0..1..0. .0..1..0..1..0..0. .0..0..1..0..1..0
..0..1..1..0..1..0. .1..0..1..0..1..1. .1..0..1..0..1..0. .1..0..1..0..1..0
..1..0..1..0..1..0. .0..1..0..1..0..1. .1..0..1..0..1..0. .1..0..1..0..1..0
..0..1..0..1..0..1. .0..1..0..1..0..1. .1..0..1..0..1..0. .1..0..1..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 17 2017
STATUS
approved