OFFSET
1,2
COMMENTS
Column 3 of A297986.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + 2*a(n-2) + a(n-3) - a(n-4) - 4*a(n-6) - 8*a(n-7) - 2*a(n-8) + 4*a(n-9) + 6*a(n-10) + 2*a(n-11) for n>13.
Empirical g.f.: x*(1 + 5*x - 6*x^2 - 10*x^3 - 7*x^4 + x^5 - 6*x^6 + 22*x^7 + 38*x^8 + 14*x^9 - 14*x^10 - 16*x^11 - 4*x^12) / ((1 - x)*(1 + x)*(1 - x - x^2 - 2*x^3 - 2*x^5 + 4*x^6 + 6*x^7 + 6*x^8 + 2*x^9)). - Colin Barker, Mar 22 2018
EXAMPLE
Some solutions for n=7:
..0..1..1. .0..1..0. .0..1..0. .0..0..1. .0..1..1. .0..1..0. .0..1..0
..0..0..1. .1..1..1. .0..0..0. .0..1..1. .0..0..1. .0..0..0. .0..0..0
..1..0..1. .0..0..0. .0..1..0. .1..0..0. .1..0..1. .0..1..0. .0..1..0
..1..1..1. .1..0..1. .1..1..0. .1..1..0. .1..1..1. .1..1..1. .1..1..0
..1..0..1. .1..1..1. .1..0..0. .0..1..0. .1..0..1. .0..0..0. .0..1..0
..1..0..0. .1..0..1. .0..1..1. .0..0..0. .0..0..1. .1..0..1. .0..0..0
..1..1..0. .0..0..0. .0..0..1. .0..1..0. .0..1..1. .0..0..0. .0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 10 2018
STATUS
approved