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%I #5 Jun 18 2022 18:56:16
%S 1,7,19,37,67,234,1126,6422,32270,161586,990365,7766402,74447984,
%T 789199485,8923308481
%N Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,2 4,2 5,3 5,4 6,3 polyhexes in any orientation on a planar n X n X n triangular grid.
%e Maximal 11 X 11 X 11 example
%e .............0
%e ............0.0
%e ...........0.1.0
%e ..........0.0.1.1
%e .........0.1.1.0.0
%e ........1.1.0.0.0.1
%e .......0.0.1.0.1.1.0
%e ......1.0.0.0.0.0.1.0
%e .....0.1.1.0.1.0.1.0.0
%e ....0.1.0.1.1.0.0.1.1.0
%e ...0.0.0.0.0.1.0.1.0.0.0
%K nonn
%O 6,2
%A _R. H. Hardin_, Jan 22 2009