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Number of planar triangular n X n X n nonnegative integer grids symmetric under 120 degree rotation with every similarly oriented 4 X 4 X 4 subtriangle summing to 5.
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%I #3 Mar 31 2012 12:35:21

%S 4,14,23,19,11,38,9,12,11,4,7,10,7,4,7,10,7,4,7,10,7,4,7,10,7,4,7,10,

%T 7,4,7,10,7,4,7,10,7,4,7,10,7,4,7,10,7,4,7,10,7,4,7,10,7,4,7,10,7

%N Number of planar triangular n X n X n nonnegative integer grids symmetric under 120 degree rotation with every similarly oriented 4 X 4 X 4 subtriangle summing to 5.

%C Pattern 4 7 10 7 starts at n=13 and continues through at least n=60.

%e Maximal zeros solution for n=13

%e ..............2

%e .............0.0

%e ............0.1.0

%e ...........0.1.1.0

%e ..........2.0.0.0.2

%e .........0.0.1.1.0.0

%e ........0.1.0.1.0.1.0

%e .......0.1.1.0.0.1.1.0

%e ......2.0.0.0.2.0.0.0.2

%e .....0.0.1.1.0.0.1.1.0.0

%e ....0.1.0.1.0.1.0.1.0.1.0

%e ...0.1.1.0.0.1.1.0.0.1.1.0

%e ..2.0.0.0.2.0.0.0.2.0.0.0.2

%K nonn

%O 4,1

%A _R. H. Hardin_ Jan 04 2009