OFFSET
1,1
COMMENTS
Column 4 of A280440.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) -4*a(n-2) -2*a(n-3) +4*a(n-4) -a(n-6) for n>7.
Empirical g.f.: 2*x + 2*x^2*(10-19*x-4*x^2+13*x^3+x^5+2*x^4) / ( (x-1)^2*(x^2+x-1)^2 ). - R. J. Mathar, Jan 04 2017
EXAMPLE
Some solutions for n=4
..0..1..1..0. .0..1..0..1. .0..1..1..0. .0..0..1..0. .0..1..0..1
..1..0..0..1. .1..0..0..0. .1..0..0..1. .1..0..1..0. .1..0..1..0
..0..1..1..0. .0..1..0..1. .0..1..1..0. .0..1..0..1. .0..1..0..1
..1..0..1..0. .1..0..1..0. .0..1..0..1. .1..0..1..0. .1..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 03 2017
STATUS
approved