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%I #3 Mar 31 2012 12:35:22
%S 1,7,19,58,329,2350,20015,218371,3090717,58164789,1393078738,
%T 42785732400,1703751776933,87700729777393,5826804979644472
%N Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 polyhexes in any orientation on a planar nXnXn triangular grid.
%e Maximal 11 X 11 X 11 example
%e .............0
%e ............1.0
%e ...........0.1.1
%e ..........1.0.0.1
%e .........1.0.0.0.0
%e ........0.1.0.0.1.1
%e .......0.1.0.1.1.0.0
%e ......1.0.0.0.0.0.1.1
%e .....1.0.1.0.0.1.1.0.0
%e ....0.1.0.1.1.0.0.0.1.1
%e ...0.1.0.0.0.1.0.1.1.0.0
%K nonn
%O 3,2
%A _R. H. Hardin_ Jan 22 2009