%I #3 Mar 31 2012 12:35:22
%S 1,4,13,37,146,620,2737,17298,136979,1185666,12752003,161758550,
%T 2364549128,42702118766
%N Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,0 3,1 4,0 polyhexes in any orientation on a planar nXnXn triangular grid.
%C Same series for 0,0 1,0 2,0 2,1 3,0 3,1 4,0 polyhexes.
%e Maximal 11 X 11 X 11 example
%e .............1
%e ............0.1
%e ...........0.1.0
%e ..........1.0.1.1
%e .........1.0.0.0.1
%e ........0.1.0.0.0.0
%e .......1.1.0.0.1.1.0
%e ......1.0.0.1.1.0.1.1
%e .....0.0.0.0.0.0.0.0.0
%e ....1.1.0.1.1.0.0.1.1.0
%e ...0.0.1.1.0.0.1.1.0.1.1
%K nonn
%O 4,2
%A _R. H. Hardin_ Jan 22 2009