OFFSET
1,1
COMMENTS
Column 2 of A222386.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) + 8*a(n-3) - 32*a(n-4) - 16*a(n-6) + 64*a(n-7).
Empirical g.f.: 2*x*(1 + 4*x - 20*x^3 + 16*x^4 + 32*x^6) / ((1 - 4*x)*(1 - 4*x^3)^2). - Colin Barker, Mar 15 2018
EXAMPLE
Some solutions for n=3:
..1..0....1..1....1..0....0..1....0..1....0..0....0..0....0..1....1..0....0..1
..0..0....0..0....1..1....0..1....0..1....0..1....0..0....1..0....0..0....0..0
..1..0....1..1....1..1....1..1....1..0....1..0....0..1....0..0....0..1....0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 18 2013
STATUS
approved