A153965 Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 9 ones in any 4 X 4 X 4 subtriangle.

1, 2, 2, 4, 15, 31, 126, 927, 3933, 31429, 472959, 4005742, 63878219, 1917687587, 32433255622, 1032580394091, 61890749905798, 2090664356692297, 132950076813594995, 15915454829832076325, 1073793991171675728498