Riemann zeta at even integers

Theorem

The following formula holds for even integers $n$ and $m \in \{1,2,3,\ldots\}$: $$\zeta(n)= \left\{ \begin{array}{ll} 0 &, \quad n=-2m, \\ -\dfrac{1}{2} &, \quad n=0 \\ \dfrac{(-1)^m B_m}{2m} &, \quad n=2m, \end{array} \right.$$ where $\zeta$ denotes Riemann zeta and $B_m$ denotes Bernoulli numbers.

References

• 1930: Edward Charles Titchmarsh: The Zeta-Function of Riemann ... (previous) ... (next): § Introduction $(5)$