OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) - 9*a(n-2) + 7*a(n-3) - 2*a(n-4).
Empirical: a(n) = 144*2^(n-1) + 42*n^2 + 69*n - 8.
Empirical g.f.: x*(247 - 649*x + 446*x^2 - 128*x^3) / ((1 - x)^3*(1 - 2*x)). - Colin Barker, Nov 15 2018
EXAMPLE
Some solutions for n=6:
..1..1..1..0..0..0....0..0..0..0..0..0....1..0..0..0..0..0....1..1..0..1..0..0
..0..0..1..0..0..0....1..1..1..1..1..1....1..0..0..0..0..0....1..1..0..1..0..0
..0..0..1..0..0..1....1..1..1..1..1..1....1..0..0..0..0..0....1..1..0..1..0..0
..0..0..1..0..0..1....1..1..1..1..1..1....1..0..0..0..0..0....1..1..0..1..0..0
..0..0..1..0..0..1....0..0..0..0..0..0....1..0..0..0..0..0....0..0..0..1..0..0
..0..0..1..0..0..1....0..0..0..0..0..0....1..1..1..1..1..1....0..0..0..1..0..0
..0..0..1..0..0..1....0..0..0..0..0..0....0..0..0..0..1..1....0..0..0..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 26 2014
STATUS
approved