A166204 - OEIS

%I #3 Mar 31 2012 12:35:35

%S 1,10,4,12,201,886,9309,405175,4285591,161588843,25012399727,

%T 703336933599,84913600697770

%N Number of nXnXn triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= 9

%e Some solutions for n=4

%e .....6........0........0........6........4........0........2........1...

%e ....0.0......2.0......1.1......0.0......0.1......0.0......1.0......1.0..

%e ...0.1.0....0.3.2....1.1.1....0.0.0....1.1.0....0.9.0....0.3.1....0.2.1.

%e ..6.0.0.6..0.2.0.0..0.1.1.0..6.0.0.6..4.0.1.4..0.0.0.0..2.1.0.2..1.1.0.1

%e ------

%e .....2........1........1........5........2........1........1........4...

%e ....1.2......2.0......0.0......1.0......1.0......1.0......0.3......0.0..

%e ...2.0.1....0.0.2....0.3.0....0.1.1....0.1.1....0.5.1....3.0.0....0.1.0.

%e ..2.1.2.2..1.2.0.1..1.0.0.1..5.1.0.5..2.1.0.2..1.1.0.1..1.0.3.1..4.0.0.4

%K nonn

%O 0,2

%A _R. H. Hardin_ Oct 09 2009