OFFSET
1,1
LINKS
R. H. Hardin,Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-2) + 10*a(n-4) + 5*a(n-6) + 2*a(n-8) - 2*a(n-10) + a(n-12) for n>13.
Empirical g.f.: x*(63 + 106*x + 89*x^2 + 248*x^3 - 56*x^4 + 144*x^5 - 35*x^6 + 46*x^7 - 16*x^8 - 50*x^9 + 18*x^10 + 26*x^11 - 7*x^12) / (1 - 3*x^2 - 10*x^4 - 5*x^6 - 2*x^8 + 2*x^10 - x^12). -Colin Barker,Dec 30 2018
EXAMPLE
Some solutions for n=4:
..1..0..1..0..0....0..1..0..0..0....1..0..1..0..0....0..1..0..1..0
..0..1..0..1..0....1..0..1..0..1....0..1..0..1..0....1..0..1..0..1
..0..0..1..0..1....0..1..0..1..0....1..0..0..0..1....0..1..0..1..0
..0..1..0..1..0....1..0..1..0..1....0..1..0..1..0....0..0..1..0..0
..1..0..1..0..0....0..0..0..1..0....1..0..1..0..1....0..1..0..1..0
..0..0..0..1..0....0..0..1..0..0....0..0..0..1..0....1..0..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin,Aug 08 2015
STATUS
approved