A153930 Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with no more than 4 ones in any 3 X 3 X 3 subtriangle.

1, 2, 4, 13, 45, 293, 1880, 22810, 274047, 6160861, 137419960, 5755708030, 238764714329, 18607726818765, 1436358552064865, 208215628095796834, 29898827223053355535, 8063377147636346175953, 2154023814255202610544411