OFFSET
1,1
COMMENTS
Column 7 of A183986.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
Index entries for linear recurrences with constant coefficients, signature (3, 0, -6, 4).
FORMULA
Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 4*a(n-4).
Conjectures from Colin Barker, Apr 09 2018: (Start)
G.f.: x*(81 - 160*x - 163*x^2 + 320*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).
a(n) = 3*2^(n/2-1) + 2^(n-1) + 78 for n even.
a(n) = 2^(n-1) + 2^((n+1)/2) + 78 for n odd.
(End)
The above empirical formula is correct. See note from Andrew Howroyd in A183986.
EXAMPLE
Some solutions for 5 X 8.
..0..0..1..1..1..1..0..1....1..1..0..1..1..0..1..1....1..0..1..0..1..0..1..0
..1..1..0..0..0..0..1..0....0..0..1..0..0..1..0..0....1..1..1..1..1..1..1..1
..0..0..1..1..1..1..0..1....1..1..0..1..1..0..1..1....0..1..0..1..0..1..0..1
..1..1..0..0..0..0..1..0....0..0..1..0..0..1..0..0....1..1..1..1..1..1..1..1
..0..0..1..1..1..1..0..1....1..1..0..1..1..0..1..1....1..0..1..0..1..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 08 2011
STATUS
approved