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%I #3 Mar 31 2012 12:35:21
%S 1,2,2,4,15,31,126,927,3933,31429,472959,4005742,63878219,1917687587,
%T 32433255622,1032580394091,61890749905798,2090664356692297,
%U 132950076813594995,15915454829832076325,1073793991171675728498
%N Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 9 ones in any 4 X 4 X 4 subtriangle.
%K nonn
%O 0,2
%A _R. H. Hardin_ Jan 03 2009