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%I #3 Mar 31 2012 12:35:21
%S 0,20,12,0,28,6,0,18,6,0,9,0,0,9,0,0,7,0,0,9,0,0,9,0,0,9,0,0,7,0,0,9,
%T 0,0,9,0,0,9,0,0,7,0,0,9,0,0,9,0,0,9,0,0,7,0,0,9,0,0
%N Number of planar triangular n X n X n nonnegative integer grids symmetric under 120 degree rotation with every similarly oriented 3 X 3 X 3 subtriangle summing to 5.
%C Pattern 0 9 0 0 9 0 0 7 0 0 9 0 starts at n=12 and continues through at least n=60.
%e Maximal zeros solution for n=13
%e ..............3
%e .............0.0
%e ............0.2.0
%e ...........1.1.1.1
%e ..........2.0.1.0.2
%e .........0.1.1.1.1.0
%e ........1.1.0.2.0.1.1
%e .......0.1.2.0.0.2.1.0
%e ......2.1.0.0.3.0.0.1.2
%e .....1.0.1.2.0.0.2.1.0.1
%e ....0.1.1.1.0.2.0.1.1.1.0
%e ...0.2.1.0.1.1.1.1.0.1.2.0
%e ..3.0.0.1.2.0.1.0.2.1.0.0.3
%K nonn
%O 3,2
%A _R. H. Hardin_ Jan 04 2009
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