OFFSET
1,1
COMMENTS
Column 4 of A188866.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 27*n - 13 for n>1.
Conjectures from Colin Barker, Feb 28 2018: (Start)
G.f.: x*(16 + 9*x + 2*x^2) / (1 - x)^2.
a(n) = 2*a(n-1) - a(n-2) for n>3.
(End)
EXAMPLE
Some solutions for 3 X 4:
..1..1..1..1....1..1..0..1....1..1..1..1....1..0..1..1....1..1..1..1
..1..1..1..1....0..0..0..0....1..1..1..0....0..0..0..0....0..0..1..0
..1..0..0..1....0..0..0..0....1..1..0..0....0..0..0..0....0..0..0..0
MATHEMATICA
Join[{16}, Range[41, 7000, 27]] (* Vladimir Joseph Stephan Orlovsky, Jul 13 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 12 2011
STATUS
approved