OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 8*a(n-1) - 20*a(n-2) + 8*a(n-3) + 33*a(n-4) - 36*a(n-5) + 8*a(n-7).
Empirical g.f.: 2*x*(59 - 284*x + 271*x^2 + 416*x^3 - 624*x^4 + 10*x^5 + 128*x^6) / ((1 - x)^2*(1 - 2*x)*(1 - 2*x - x^2)*(1 - 2*x - 4*x^2)). - Colin Barker, Nov 20 2018
EXAMPLE
Some solutions for n=4:
..1..0..0..1..0....0..0..0..1..0....0..0..0..1..0....1..1..1..0..1
..1..1..1..0..1....0..0..0..0..1....0..0..0..1..0....1..1..1..0..0
..1..1..1..0..1....0..0..0..1..0....0..0..0..0..1....1..1..1..0..1
..1..1..1..0..1....0..0..0..0..1....0..0..1..1..0....1..1..1..1..0
..1..1..1..0..1....0..0..0..1..0....0..0..1..1..0....1..1..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 27 2014
STATUS
approved