OFFSET
1,4
COMMENTS
Row 10 of A187507.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..50
FORMULA
Empirical: a(n) = 3603*n^2 - 28504*n + 54377 for n>8.
Conjectures from Colin Barker, Apr 24 2018: (Start)
G.f.: x^4*(398 + 2674*x + 3386*x^2 + 1366*x^3 - 172*x^4 - 324*x^5 - 107*x^6 - 15*x^7) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>11.
(End)
EXAMPLE
Some solutions for 4 X 4:
..1..0..0..0....7..8..9.10....0..7..8..9....0..5..0..1....0..0..0..1
..2..3..4..5....0..6..0..0....4..5..6.10....8..6..4..2....0..0..0..2
..0.10..8..6....0..4..5..0....0..3..1..0....9..7..0..3....9..7..5..3
..0..0..9..7....1..2..3..0....0..0..2..0...10..0..0..0...10..8..6..4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 10 2011
STATUS
approved