OFFSET
1,1
COMMENTS
Column 3 of A188824.
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) + a(n-4).
Conjectures from Colin Barker, Apr 29 2018: (Start)
G.f.: x*(8 + 9*x - 2*x^2 + x^3) / ((1 - x)^3*(1 + x)).
a(n) = (2 + 8*n + 8*n^2) / 2 for n even.
a(n) = (8*n + 8*n^2) / 2 for n odd.
(End)
EXAMPLE
Some solutions for 4 X 3:
..1..1..1....1..1..1....1..1..0....1..1..1....1..0..1....0..1..0....0..1..0
..0..1..1....1..1..1....1..0..1....1..1..1....0..0..0....1..0..1....1..0..1
..1..0..1....1..0..0....0..1..0....1..1..1....0..0..0....0..0..0....0..1..0
..0..0..0....0..0..0....0..0..1....1..1..1....0..0..0....0..0..0....1..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 11 2011
STATUS
approved