A153900 - OEIS

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A153900

Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with no more than 1 one in any 3 X 3 X 3 subtriangle.

%I #5 Apr 28 2021 00:12:55

%S 1,2,2,3,5,10,18,48,97,299,769,2879,9061,41454,154622,857522,3902066,

%T 26137942,144826739,1177942368,7878440446,77715100928,630332738835,

%U 7530329483705,74116147914872,1073536700395590,12799994974031763

%N Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude 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