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Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 3 ones in any 3 X 3 X 3 subtriangle.
0

%I #5 Apr 28 2021 00:16:38

%S 1,2,2,3,4,8,13,36,59,160,431,1207,3281,14493,40909,190825,830228,

%T 4020596,18120315,138139135,645018986,5068850751,37171002203,

%U 301985114648,2294433300268,29211683338424,229716243590382

%N Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 3 ones in any 3 X 3 X 3 subtriangle.

%K nonn

%O 0,2

%A _R. H. Hardin_, Jan 03 2009