Ω
i
ℓ
=
1
m
=
−
1
m
=
0
m
=
1
m
=
−
2
m
=
−
1
m
=
0
m
=
1
m
=
2
m
=
−
3
m
=
−
2
m
=
−
1
m
=
0
m
=
1
m
=
2
m
=
3
Figure courtesy of Joel Ong