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%I #3 Mar 31 2012 12:35:35
%S 1,4,2,3,14,30,89,553,1588,8865,104510,444424,4173156,81325310,
%T 652489468,10459516337,342881668736,4580518588744,125220290825340,
%U 7022575980797573,156952369257684587
%N Number of nXnXn triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= 3
%e All solutions for n=4
%e .....1........0........0........2........1........1........0........0...
%e ....0.1......0.1......0.0......0.0......0.0......0.0......0.0......1.0..
%e ...1.0.0....1.0.0....0.2.0....0.1.0....0.1.0....0.2.0....0.3.0....0.0.1.
%e ..1.0.1.1..0.0.1.0..0.0.0.0..2.0.0.2..1.0.0.1..1.0.0.1..0.0.0.0..0.1.0.0
%e ------
%e .....0........1........1........0........2........3...
%e ....0.0......1.0......0.0......0.0......0.0......0.0..
%e ...0.0.0....0.0.1....0.0.0....0.1.0....0.0.0....0.0.0.
%e ..0.0.0.0..1.1.0.1..1.0.0.1..0.0.0.0..2.0.0.2..3.0.0.3
%K nonn
%O 0,2
%A _R. H. Hardin_ Oct 09 2009
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