OFFSET
1,1
COMMENTS
Column 4 of A299595.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4) -a(n-5) -a(n-6) for n>9.
Empirical g.f.: x*(5 + x^2 - 8*x^3 - x^4 + 12*x^5 + 6*x^6 - 4*x^7 - 3*x^8) / ((1 + x^2 - x^3)*(1 - x - 2*x^2 - x^3)). - Colin Barker, Feb 15 2018
EXAMPLE
Some solutions for n=5:
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..0
..1..0..0..0. .0..0..0..1. .0..0..0..0. .0..0..0..1. .0..0..0..0
..0..0..0..0. .1..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0
..0..0..0..0. .0..0..0..0. .0..0..0..1. .0..0..0..0. .1..0..0..0
..0..0..0..0. .0..1..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 13 2018
STATUS
approved