OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 10*a(n-1) - 40*a(n-2) + 82*a(n-3) - 91*a(n-4) + 52*a(n-5) - 12*a(n-6).
Conjectures from Colin Barker, Nov 23 2018: (Start)
G.f.: x*(125 - 819*x + 2015*x^2 - 2393*x^3 + 1392*x^4 - 324*x^5) / ((1 - x)^3*(1 - 2*x)^2*(1 - 3*x)).
a(n) = 23/2 - 2^(4+n) + (7*3^(2+n))/2 + 2*n + 3*2^(3+n)*n + n^2.
(End)
EXAMPLE
Some solutions for n=4:
..1..0..1..0..0....0..0..0..0..0....2..2..1..0..0....1..1..1..1..0
..2..1..2..1..1....0..0..0..0..0....2..2..1..0..1....1..1..1..1..0
..2..1..2..1..1....1..2..2..2..2....2..2..1..0..1....0..2..2..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 28 2014
STATUS
approved