OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) + 10*a(n-2) - 32*a(n-3) - 47*a(n-4) + 40*a(n-5) + 38*a(n-6) - 12*a(n-7) - 9*a(n-8).
Empirical g.f.: x*(5 + 24*x - 3*x^2 - 24*x^3 - 9*x^4) / (1 - 2*x - 7*x^2 + 2*x^3 + 3*x^4)^2. - Colin Barker, Jan 14 2019
EXAMPLE
Some solutions for n=4:
..1..0..0..0. .1..0..0..0. .1..0..1..0. .0..0..0..1. .0..0..1..0
..0..0..0..0. .0..0..1..1. .0..0..0..0. .1..0..0..0. .0..0..0..0
..1..0..0..0. .0..0..0..0. .0..0..0..1. .0..0..0..1. .0..0..1..1
..1..0..0..1. .1..0..0..1. .0..0..1..0. .0..0..0..1. .1..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 13 2016
STATUS
approved