OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..37
FORMULA
Empirical: a(n) = a(n-1) + 4*a(n-2) - 3*a(n-3) + 3*a(n-4) - 6*a(n-5) - 9*a(n-6) + 3*a(n-7) + 2*a(n-8) + a(n-9) + a(n-10).
Empirical g.f.: x*(1 + 3*x + 3*x^2 + 2*x^3 - x^4 - 5*x^5 - 4*x^6 + 3*x^7 - x^8 + x^9) / ((1 - x - x^2)*(1 + x^2 - x^4)*(1 - 4*x^2 - x^4)). - Colin Barker, Mar 27 2018
EXAMPLE
Some solutions for 5 X 5 X 5 with a(1,1)=0:
......0..........0..........0..........0..........0..........0..........0
.....1.1........0.0........0.1........1.1........0.0........1.1........0.0
....1.1.1......0.0.0......0.1.1......1.1.1......0.0.1......1.1.1......0.0.0
...0.0.0.0....1.1.1.1....0.1.1.0....0.0.0.0....0.0.1.1....1.1.1.1....1.1.1.1
..0.0.0.0.0..0.1.1.1.0..0.1.1.0.0..1.0.0.0.1..0.0.1.1.1..0.0.0.0.0..1.1.1.1.0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 03 2011
STATUS
approved