an,km⁡(γ2)=(-1)k⁢(n+2⁢k+12)⁢(n-m+2⁢k)!(n+m+2⁢k)!⁢∫-11Psnm⁡(x,γ2)⁢Pn+2⁢km⁡(x)⁢ⅆ⁡x.