OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 13*n^4 + 121*n^3 + 439*n^2 + 573*n + 243.
Conjectures from Colin Barker, Nov 21 2018: (Start)
G.f.: x*(1389 - 2624*x + 2518*x^2 - 1214*x^3 + 243*x^4) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)
EXAMPLE
Some solutions for n=4:
..0..0..0..0..0....2..2..1..1..0....2..2..2..1..0....2..2..2..2..1
..0..0..0..2..2....0..0..0..0..0....0..0..0..0..1....0..0..0..0..0
..0..0..0..2..2....2..2..2..2..2....0..0..0..1..2....1..1..1..1..1
..0..0..0..2..2....0..0..1..1..1....0..0..0..1..2....1..1..1..2..2
..0..0..0..2..2....1..1..2..2..2....0..0..0..1..2....1..1..1..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 27 2014
STATUS
approved