OFFSET
1,2
COMMENTS
Row 5 of A187162.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..50
FORMULA
Empirical: a(n) = 726*n^3 - 2640*n^2 + 2688*n - 720 for n>3.
Conjectures from Colin Barker, Apr 20 2018: (Start)
G.f.: 6*x^2*(24 + 444*x + 360*x^2 - 115*x^3 + 4*x^4 + 9*x^5) / (1 - x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>7.
(End)
EXAMPLE
A solution for 2 X 2 X 2:
..5..0.....4..1
..0..0.....3..2
CROSSREFS
KEYWORD
nonn,walk
AUTHOR
R. H. Hardin, Mar 06 2011
STATUS
approved