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*(10875 - 99285*x + 368950*x^2 - 715664*x^3 + 755858*x^4 - 402400*x^5 + 50022*x^6 + 63432*x^7 - 26568*x^8) / ((1 - x)^3*(1 - 2*x)^3*(1 - 3*x)).
a(n) = (-8787 + 3389*2^n + 169*3^(3+n) + (14186-99*2^(4+n))*n + 36*(145+33*2^(1+n))*n^2) / 4 for n>2.
(End)
EXAMPLE
Some solutions for n=3:
..2..1..1..0..0..1..0....0..1..1..1..0..0..0....0..1..0..1..0..0..0
..1..2..2..1..1..2..1....0..1..1..1..0..0..0....0..1..0..1..0..0..0
..0..1..1..0..0..1..0....0..1..1..1..1..1..1....0..1..0..1..0..0..0
..0..1..1..0..0..2..1....0..1..1..1..1..2..2....0..1..0..2..2..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 28 2014
STATUS
approved