OFFSET
1,1
COMMENTS
Column 3 of A228285.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
a(n) = a(n-1) + 5*a(n-2) + 4*a(n-3) - a(n-5).
G.f.: x*(2 + x - x^3) / ((1 + x)*(1 - 2*x - 3*x^2 - x^3 + x^4)). - Colin Barker, Mar 16 2018
EXAMPLE
Some solutions for n=4:
..1..0..0....1..0..0....1..0..0....1..0..1....1..0..0....1..0..1....1..0..0
..0..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..0..0....0..0..0
..0..0..1....0..0..0....0..0..0....0..0..0....1..0..0....0..0..1....0..1..0
..0..0..0....1..0..1....1..0..0....0..1..0....0..0..1....0..1..0....1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 19 2013
EXTENSIONS
Edited by N. J. A. Sloane, Aug 22 2013
STATUS
approved