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%I #3 Mar 31 2012 12:35:35
%S 1,7,3,7,66,218,1340,25771,157803,2661967,140020892,1770255356,
%T 73044448611,8966527587527,317675182498031
%N Number of nXnXn triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= 6
%e Some solutions for n=4
%e .....1........2........0........1........0........4........3........1...
%e ....0.0......0.0......1.0......0.1......1.1......0.0......1.0......1.0..
%e ...0.5.0....0.1.0....0.1.1....1.1.0....1.0.1....0.0.0....0.1.1....0.3.1.
%e ..1.0.0.1..2.0.0.2..0.1.0.0..1.0.1.1..0.1.1.0..4.0.0.4..3.1.0.3..1.1.0.1
%e ------
%e .....0........0........4........3........1........3........0........3...
%e ....0.0......0.0......0.0......0.1......1.0......1.0......0.0......1.1..
%e ...0.4.0....0.3.0....0.1.0....1.1.0....0.1.1....0.0.1....0.6.0....1.0.1.
%e ..0.0.0.0..0.0.0.0..4.0.0.4..3.0.1.3..1.1.0.1..3.1.0.3..0.0.0.0..3.1.1.3
%K nonn
%O 0,2
%A _R. H. Hardin_ Oct 09 2009
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