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 A154043 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. 0

%I

%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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Last modified December 14 22:42 EST 2019. Contains 329987 sequences. (Running on oeis4.)