OFFSET
1,1
COMMENTS
Column 2 of A183811.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 3*a(n-1) + 9*a(n-2) - 15*a(n-3).
Empirical g.f.: x*(3 + 4*x - 11*x^2) / (1 - 3*x - 9*x^2 + 15*x^3). - Colin Barker, Apr 04 2018
EXAMPLE
Some solutions with upper left block zero for 5 X 3:
0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1
0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 0 1
0 1 1 1 1 1 1 1 1 1 1 0 1 1 0 1 0 0 0 1 0
0 1 1 1 1 0 1 0 0 1 0 0 1 1 1 0 1 1 1 1 0
1 1 0 0 1 0 0 0 1 0 0 1 0 0 1 0 1 0 1 1 1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2011
STATUS
approved