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%I #3 Mar 31 2012 12:35:23
%S 1,7,19,37,115,485,2457,16347,114526,862126,8042696,92458257,
%T 1277007692,21027306771,403213961051,9036952144101
%N Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 3,1 4,2 5,2 5,3 polyhexes in any orientation on a planar nXnXn triangular grid.
%e Maximal 12 X 12 X 12 example
%e ..............0
%e .............0.0
%e ............0.0.0
%e ...........0.0.0.0
%e ..........1.1.0.1.1
%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 ......1.0.1.1.0.1.1.0.1
%e .....1.1.0.0.0.0.0.0.1.1
%e ....0.0.1.1.1.0.1.1.1.0.0
%e ...0.0.0.0.1.0.0.1.0.0.0.0
%K nonn
%O 5,2
%A _R. H. Hardin_ Jan 22 2009