%N The number of distinct planes defined by an n X n X n grid of points.
%e The 8 points of the 2 X 2 X 2 grid define 20 planes: the 6 faces of the cube, 6 planes formed by an edge and its opposite edge, and 8 planes defined by the three vertices surrounding a given vertex. So, a(2)=20.
%Y Cf. A222267, A270579.
%A _Clive Tooth_, Mar 19 2016