Better:
\begin{align*}
L_{r_2}(s , \chi) = \sum_{0\leq n\leq r^2} {r_2(n) \chi(n) \over n^s}, \qquad \chi(n) = 1 \, \forall n
\end{align*}
Sum of Squares
## Results 
# Examples
Better:
\begin{align*}
L_{r_2}(s , \chi) = \sum_{0\leq n\leq r^2} {r_2(n) \chi(n) \over n^s}, \qquad \chi(n) = 1 \, \forall n
\end{align*}
## Results # Examples