A153929 - OEIS

A153929

Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 4 ones in any 3 X 3 X 3 subtriangle.

%I #5 Apr 28 2021 00:17:24

%S 1,2,2,3,13,21,81,653,2032,13521,198411,1134105,14051578,384943878,

%T 4075092077,94920910164,4841696508264,95471746290629,4126780473485202,

%U 391264740388006351,14349686703845230194,1153837260755381339313

%N Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 4 ones in any 3 X 3 X 3 subtriangle.

%K nonn

%O 0,2

%A _R. H. Hardin_, Jan 03 2009