%I #3 Mar 31 2012 12:35:23

%S 1,7,19,64,211,828,3688,18091,101434,633477,4772999,40520506

%N Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,1 4,1 5,2 6,2 7,2 polyhexes in any orientation on a planar nXnXn triangular grid.

%e Maximal 10 X 10 X 10 example

%e ............0

%e ...........0.0

%e ..........1.0.1

%e .........1.0.0.1

%e ........1.0.0.0.1

%e .......0.1.0.0.1.0

%e ......0.1.0.0.0.1.0

%e .....0.0.1.0.0.1.0.0

%e ....0.0.1.0.0.0.1.0.0

%e ...0.0.1.0.0.0.0.1.0.0

%K nonn

%O 7,2

%A _R. H. Hardin_ Jan 22 2009