OFFSET
1,3
COMMENTS
Row 5 of A187857.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..50
FORMULA
Empirical: a(n) = 3763*n^2 - 25044*n + 40644 for n>7.
Conjectures from Colin Barker, Apr 26 2018: (Start)
G.f.: x^3*(486 + 1862*x + 3484*x^2 + 352*x^3 + 2508*x^4 - 1488*x^5 + 977*x^6 - 655*x^7) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>10.
(End)
EXAMPLE
Some solutions for 4 X 4:
..0..1..0..0....0..0..2..0....0..0..0..0....0..0..5..0....0..0..0..0
..0..0..0..4....0..0..1..0....1..0..0..0....4..1..0..0....0..4..3..5
..0..2..0..3....5..4..3..0....5..0..0..0....0..3..0..0....0..0..2..0
..0..0..5..0....0..0..0..0....4..3..2..0....0..2..0..0....0..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 14 2011
STATUS
approved