Yl,m⁡(θ,ϕ)=(-1)l+m2l⁢l!⁢((l-m)!⁢(2⁢l+1)4⁢π⁢(l+m)!)1/2⁢ⅇⅈ⁢m⁢ϕ⁢(sin⁡θ)m⁢(ⅆⅆ⁡(cos⁡θ))l+m⁡(sin⁡θ)2⁢l.