OFFSET
1,1
COMMENTS
Row 7 of A208688.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + 39*a(n-2) + 9*a(n-3) - 180*a(n-4).
Empirical g.f.: 31*x*(1 + 30*x + 9*x^2 - 180*x^3) / ((1 + 5*x)*(1 - 6*x - 9*x^2 + 36*x^3)). - Colin Barker, Jul 05 2018
EXAMPLE
Some solutions for n=4:
..0..1..0..1....0..1..1..0....0..1..0..1....1..0..1..1....1..1..0..0
..0..1..1..0....0..1..1..1....1..1..0..1....1..0..1..1....1..1..0..1
..1..1..0..0....0..1..0..0....0..1..1..0....1..0..1..0....0..1..1..0
..0..1..0..0....1..1..0..0....0..1..0..0....1..1..1..0....0..1..0..0
..0..1..1..0....0..1..0..1....0..1..0..0....1..0..1..1....1..1..0..0
..0..1..0..1....0..1..0..0....1..1..0..1....1..0..1..0....0..1..0..1
..1..1..0..0....1..0..1..0....0..1..0..0....1..0..1..0....0..1..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 01 2012
STATUS
approved