OFFSET
1,1
COMMENTS
Row 2 of A221666.
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.: 4*x*(1 - x + 4*x^2 - 8*x^3 + 16*x^6) / ((1 - 4*x)*(1 - 4*x^3)^2). - Colin Barker, Aug 10 2018
EXAMPLE
Some solutions for n=3:
..0..0..0....0..1..0....0..1..1....0..1..1....1..1..0....0..0..1....1..0..1
..1..1..1....0..1..0....0..1..1....0..1..0....1..1..1....0..1..1....0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 21 2013
STATUS
approved