OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 10*a(n-1) - 33*a(n-2) + 24*a(n-3) + 79*a(n-4) - 138*a(n-5) - 3*a(n-6) + 100*a(n-7) - 18*a(n-8) - 20*a(n-9).
Empirical g.f.: 2*x*(126 - 841*x + 1356*x^2 + 1552*x^3 - 4886*x^4 + 609*x^5 + 3484*x^6 - 580*x^7 - 640*x^8) / ((1 - x)^2*(1 - 2*x)*(1 - 2*x - x^2)*(1 - 2*x - 2*x^2)*(1 - 2*x - 5*x^2)). - Colin Barker, Nov 20 2018
EXAMPLE
Some solutions for n=4:
..0..0..0..0..0..1....0..1..0..1..0..0....1..0..1..0..1..0....1..0..0..0..0..0
..0..0..0..0..0..1....0..1..0..1..0..1....1..0..1..0..0..1....1..0..0..0..0..0
..0..0..0..0..1..0....0..1..0..1..1..0....1..0..1..0..1..0....1..0..0..0..0..1
..0..0..0..1..0..1....0..1..0..1..1..1....0..1..0..1..0..1....1..0..0..0..1..0
..0..0..0..0..1..0....0..1..0..1..1..1....0..0..1..0..1..0....1..0..0..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 27 2014
STATUS
approved