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%I #3 Mar 31 2012 12:35:22
%S 1,7,19,37,88,640,5031,26752,151436,1596386,24274062,343210818,
%T 4865294909,96524596845,2686621268327,85799102830215
%N Number of ways to place zero or more nonadjacent 2,1 2,2 3,0 3,1 4,2 4,3 polyhexes in any orientation on a planar nXnXn triangular grid.
%C Same series for 1,1 2,0 2,1 2,2 3,1 3,2 4,3 polyhexes.
%e Maximal 13 X 13 X 13 example
%e ...............0
%e ..............1.0
%e .............1.0.1
%e ............0.1.1.0
%e ...........0.1.0.0.0
%e ..........0.0.0.0.0.1
%e .........0.0.0.0.1.0.1
%e ........0.1.1.0.0.1.1.0
%e .......0.0.0.1.1.0.0.1.0
%e ......0.0.1.1.0.0.1.0.0.1
%e .....1.1.0.0.0.1.1.0.1.0.1
%e ....0.0.1.1.0.1.0.1.0.1.1.0
%e ...0.1.1.0.0.0.0.1.0.0.0.1.0
%K nonn
%O 4,2
%A _R. H. Hardin_ Jan 22 2009