A153940 - OEIS

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A153940

Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 5 ones in any 3 X 3 X 3 subtriangle.

%I #5 Apr 28 2021 00:19:18

%S 1,2,2,3,7,12,23,97,172,639,2729,9135,35231,283089,990826,7193827,

%T 60573511,397978987,3029188158,47855760575,329376229908,4705117486982,

%U 77869569220480,1005969603691107,15055192931186105,467694688000143716

%N Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 5 ones in any 3 X 3 X 3 subtriangle.

%K nonn

%O 0,2

%A _R. H. Hardin_, Jan 03 2009