Waring Formula

$$A^n+B^n=\sum_{j=0}^{\left\lfloor{n/2}\right\rfloor } (-1)^j {n\over n-j} {n-j\choose j} (AB)^j (A+B)^{n-2j},$$

where $\left\lfloor{x}\right\rfloor$ is the Floor Function and ${n\choose k}$ is a Binomial Coefficient.

See also Fermat's Last Theorem