OFFSET
1,1
COMMENTS
Column 3 of A204381.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) -a(n-4) -a(n-5) for n>8.
Empirical g.f.: x*(78 - 24*x - 71*x^2 - 118*x^3 - 14*x^4 + 37*x^5 + 8*x^6 + 4*x^7) / ((1 - x)*(1 - x - x^2)*(1 + x + x^2)). - Colin Barker, Jun 07 2018
EXAMPLE
Some solutions for n=3:
..0..0..1..0..0....0..1..1..0..0....0..1..1..0..1....0..1..1..0..0
..0..0..1..0..0....0..1..1..1..1....0..1..1..0..1....0..1..1..0..0
..0..0..1..0..0....0..1..1..0..1....0..1..1..0..1....0..1..1..0..0
..0..0..1..0..0....1..1..1..0..1....1..1..1..0..1....0..1..1..0..0
..0..0..1..0..0....0..1..1..0..1....0..1..1..0..1....1..1..1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 14 2012
STATUS
approved