{j1j2j3l1l2l3}=∑s(-1)s⁢(s+1)!(s-j1-j2-j3)!⁢(s-j1-l2-l3)!⁢(s-l1-j2-l3)!⁢(s-l1-l2-j3)!⁢1(j1+j2+l1+l2-s)!⁢(j2+j3+l2+l3-s)!⁢(j3+j1+l3+l1-s)!,