OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 12*a(n-1) - 60*a(n-2) + 162*a(n-3) - 255*a(n-4) + 234*a(n-5) - 116*a(n-6) + 24*a(n-7) for n>9.
Conjectures from Colin Barker, Nov 23 2018: (Start)
G.f.: x*(1229 - 10881*x + 39723*x^2 - 76719*x^3 + 81484*x^4 - 42988*x^5 + 4192*x^6 + 6688*x^7 - 2560*x^8) / ((1 - x)^3*(1 - 2*x)^3*(1 - 3*x)).
a(n) = -265 - 21*2^n + 9604*3^(-3+n) + (226-9*2^(3+n))*n + 6*(7+9*2^n)*n^2 for n>2.
(End)
EXAMPLE
Some solutions for n=4:
..1..0..1..0..1....1..1..0..0..0....2..1..1..1..0....1..2..1..0..0
..1..1..2..1..2....2..2..1..1..2....2..1..1..1..1....1..2..1..0..0
..1..1..2..1..2....1..1..0..0..1....2..1..1..1..1....1..2..2..1..2
..0..0..1..0..1....1..1..0..0..2....2..1..1..2..2....0..1..1..0..1
..0..0..1..0..2....1..1..0..0..2....2..1..1..2..2....0..2..2..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 28 2014
STATUS
approved