OFFSET
1,4
COMMENTS
Row 6 of A187155.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..50
FORMULA
Empirical: a(n) = 284*n^2 - 1992*n + 3316 for n>4.
Conjectures from Colin Barker, Apr 20 2018: (Start)
G.f.: 4*x^4*(14 + 72*x + 97*x^2 - 41*x^3) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>7.
(End)
EXAMPLE
Some solutions for 4 X 4:
..0..3..0..0....0..0..2..0....0..0..5..0....0..0..4..0....0..3..0..0
..4..0..2..0....0..1..0..3....0..4..0..6....0..5..0..3....2..0..4..0
..0..5..0..1....6..0..4..0....3..0..1..0....6..0..2..0....0..1..0..5
..0..0..6..0....0..5..0..0....0..2..0..0....0..1..0..0....0..0..6..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 06 2011
STATUS
approved