OFFSET
1,1
COMMENTS
Column 5 of A208709.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 24*a(n-1) - 28*a(n-2) + 16*a(n-3) for n>4.
Empirical g.f.: 4*x*(4 - 7*x + 8*x^2 - 4*x^3) / (1 - 24*x + 28*x^2 - 16*x^3). - Colin Barker, Jul 06 2018
EXAMPLE
Some solutions for n=4:
..0..0..1..0..0....0..0..1..0..0....0..0..1..1..1....0..1..1..0..1
..1..1..0..1..0....1..1..1..1..0....0..1..0..0..0....1..0..1..0..0
..1..0..1..1..0....1..0..1..1..0....0..0..1..0..0....1..0..1..1..1
..0..1..0..1..0....1..1..0..0..1....1..1..1..0..1....0..0..1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 01 2012
STATUS
approved