OFFSET
1,1
COMMENTS
Column 3 of A186462.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 2*a(n-1) - 2*a(n-3) + 2*a(n-4) - a(n-5) for n>9.
Empirical g.f.: x*(42 - 33*x + 9*x^2 + 24*x^3 - 36*x^4 - 16*x^5 + 19*x^6 - 7*x^7 + 16*x^8) / ((1 - x)*(1 - x - x^2 + x^3 - x^4)). - Colin Barker, Apr 17 2018
EXAMPLE
Some solutions for 3 X 4:
..1..0..0..0....1..1..0..1....0..0..0..0....0..0..0..1....1..0..0..1
..0..0..0..0....1..0..1..0....1..0..0..0....0..0..0..0....1..0..0..0
..0..0..0..0....0..1..0..1....1..1..0..0....1..0..0..0....1..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 22 2011
STATUS
approved