OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-2) + 6*a(n-4) + 4*a(n-6) - a(n-8) for n>10.
Empirical g.f.: x*(48 + 68*x + 98*x^2 + 211*x^3 + 34*x^4 + 144*x^5 - 8*x^6 - 27*x^7 + 2*x^8 - 3*x^9) / ((1 + x + 2*x^3 - x^4)*(1 - x - 2*x^3 - x^4)). - Colin Barker, Dec 29 2018
EXAMPLE
Some solutions for n=4:
..0..1..0..1....0..0..1..0....1..0..1..0....0..1..0..0....1..0..0..1
..0..0..1..0....1..0..0..1....0..1..0..0....1..0..1..0....1..0..1..0
..0..1..0..0....1..0..1..0....1..0..1..0....0..1..0..1....0..1..0..1
..1..0..1..0....0..1..0..1....0..1..0..1....1..0..0..0....0..0..1..0
..0..1..0..1....0..0..1..0....1..0..0..0....0..1..0..1....0..1..0..0
..1..0..0..1....1..1..0..0....0..1..0..0....1..0..1..0....1..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 04 2015
STATUS
approved