A153899 - OEIS

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A153899

Number of planar n X n X n binary triangular grids symmetric under 120-degree rotation with no more than 1 one in any 3 X 3 X 3 subtriangle.

%I #8 Feb 25 2023 18:06:56

%S 1,2,1,1,3,4,6,13,17,34,101,146,325,1195,2277,6460,27376,61961,214755,

%T 1116386,3024411,12485340,79544755,263062079,1324332721,10146383904,

%U 40752385354,249319033030,2314746073775,11234416498141,83071107149999

%N Number of planar n X n X n binary triangular grids symmetric under 120-degree rotation with no more than 1 one in any 3 X 3 X 3 subtriangle.

%K nonn

%O 0,2

%A _R. H. Hardin_, Jan 03 2009