OFFSET
1,1
COMMENTS
Column 4 of A189449.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 12*a(n-1) -12*a(n-2) +12*a(n-3) -12*a(n-4) +a(n-5).
Empirical g.f.: x*(5 + x - 6*x^2 - 20*x^3 + 2*x^4) / ((1 - x)*(1 - 11*x + x^2 - 11*x^3 + x^4)). - Colin Barker, May 02 2018
EXAMPLE
Some solutions for 3 X 4:
..0..1..3..2....1..0..2..3....5..1..2..3....5..1..3..2....0..6..2..3
..4..5..7..6....9.10.11..7....9..0..7..6....4..0..7..6....9..4..1..7
..9..8.11.10....8..4..5..6....8..4.11.10....8..9.11.10....8.10..5.11
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 22 2011
STATUS
approved