OFFSET
1,1
COMMENTS
Column 3 of A218897.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) + 2*a(n-2) - 5*a(n-3) - 8*a(n-4) - 4*a(n-5).
Empirical g.f.: 2*x*(2 + x - 4*x^2 - 9*x^3 - 2*x^4) / (1 - 4*x - 2*x^2 + 5*x^3 + 8*x^4 + 4*x^5). - Colin Barker, Jul 24 2018
EXAMPLE
Some solutions for n=3:
..0..0..1....1..0..1....0..0..0....0..0..0....0..0..1....0..0..0....0..0..1
..1..0..1....0..0..0....0..0..0....1..0..0....0..0..1....0..0..0....1..0..0
..0..0..0....1..0..0....0..0..0....1..0..1....1..0..1....1..0..1....1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 08 2012
STATUS
approved