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%I #3 Mar 31 2012 12:35:23
%S 1,7,19,70,241,813,4400,23369,158297,1249218,10771936,115482200
%N Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,0 4,1 5,2 6,3 polyhexes in any orientation on a planar nXnXn triangular grid.
%e Maximal 12 X 12 X 12 example
%e ..............0
%e .............0.1
%e ............0.0.1
%e ...........0.0.0.1
%e ..........0.0.0.0.1
%e .........1.0.0.0.1.0
%e ........1.0.0.0.1.0.1
%e .......1.0.0.0.1.0.1.0
%e ......1.0.0.0.0.0.1.0.1
%e .....0.1.0.1.1.1.1.0.1.0
%e ....0.0.1.0.0.0.0.0.1.0.0
%e ...0.0.0.1.0.1.1.1.1.0.0.0
%K nonn
%O 6,2
%A _R. H. Hardin_ Jan 22 2009