a(2)=1, because there exists only one normalized configuration (removing rotations and reflections) with
A280537(2)=5 points: (0,0,0),(0,0,1),(0,1,0),(1,0,0),(1,1,1).
a(3)=1, because there exists only one normalized configuration with
A280537(3)=8 points: (0,0,0),(0,1,1),(0,1,2),(1,0,1),(1,1,0),(1,2,0),(2,0,1),(2,2,2).
