real analysis - solve the limit of $(y_{n})$, $y_{n}=1+frac{1}{3^{2}}+...+frac{1}{(2n-1)^{2}}$

I have the following sequence $(x_{n})$ , $x_{n}=1+\frac{1}{2^{2}}+...+\frac{1}{n^{2}}$ which has the limit $\frac{\pi ^{2}}{6}$.I need to calculate the limit of the sequence $(y_{n})$, $y_{n}=1+\frac{1}{3^{2}}+...+\frac{1}{(2n-1)^{2}}$

I don't know how to start.I think I need to solve the limit for the whole sequence ( even n + odd n) then from the "big limit" I should subtract $\frac{\pi ^{2}}{6}$, right?