A153918 Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with no more than 2 ones in any 5 X 5 X 5 subtriangle.

1, 2, 3, 6, 8, 13, 27, 79, 206, 623, 1643, 6478, 21771, 102958, 407720, 2191304, 10858499, 72602092, 437224300, 3520328145, 25109099300, 244666233084, 2097356566526, 24692650522065, 255493996817129, 3611171350858856