{\displaystyle {\begin{aligned}V&={\frac {GM}{r}}\left(1-\sum _{n=2}^{\infty }J_{n}\left({\frac {R}{r}}\right)^{n}P_{n}(\sin \theta )\right.\\&+\left.\sum _{n=2}^{\infty }\sum _{m=1}^{n}\left({\frac {R}{r}}\right)^{n}(C_{nm}\cos m\lambda +S_{nm}\sin m\lambda )P_{n}^{m}(\sin \theta )\right),\\\end{aligned}}}