OFFSET
1,1
COMMENTS
Column 4 of A183632.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
Robert Israel, Maple-assisted proof of empirical formula
Index entries for linear recurrences with constant coefficients, signature (6,-11,6).
FORMULA
Empirical: a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3).
Conjectures from Colin Barker, Mar 30 2018: (Start)
G.f.: 3*x*(103 - 469*x + 486*x^2) / ((1 - x)*(1 - 2*x)*(1 - 3*x)).
a(n) = 3*(60 + 5*2^(2+n) + 3^n).
(End)
Formula and conjectures confirmed by Robert Israel, Mar 30 2018 (see link).
EXAMPLE
Some solutions for 3 X 5:
2 1 2 0 2 0 2 1 2 1 1 1 0 2 0 2 0 1 2 0
1 0 1 1 1 2 0 1 0 1 1 1 2 0 2 0 2 1 0 2
1 2 1 1 1 0 2 1 2 1 1 1 0 2 0 2 0 1 2 0
MAPLE
seq(3*(60 + 5*2^(2+n) + 3^n), n=1..30); # Robert Israel, Mar 30 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2011
STATUS
approved