OFFSET
1,1
COMMENTS
Row 4 of A207717.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) +10*a(n-2) -8*a(n-3) -9*a(n-4) +6*a(n-5).
Empirical g.f.: 9*x*(1 - x)*(1 + 6*x + 3*x^2 - 6*x^3) / (1 - 4*x - 10*x^2 + 8*x^3 + 9*x^4 - 6*x^5). - Colin Barker, Jun 25 2018
EXAMPLE
Some solutions for n=4:
..1..0..1..0....1..0..1..0....1..1..0..0....0..1..0..1....1..0..1..1
..0..1..1..0....1..0..1..0....1..1..1..0....1..1..1..0....1..0..1..1
..1..0..1..0....1..0..1..0....1..0..1..0....0..1..0..1....1..0..1..1
..0..1..1..0....1..0..1..0....0..1..1..0....1..0..1..1....1..0..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 19 2012
STATUS
approved