Question Number 135647 by Dwaipayan Shikari last updated on 14/Mar/21
$$…+\frac{\mathrm{1}}{\left(\mathrm{1}−\mathrm{2}\pi^{\mathrm{2}} \right)^{\mathrm{2}} }+\frac{\mathrm{1}}{\left(\mathrm{1}−\pi^{\mathrm{2}} \right)^{\mathrm{2}} }+\mathrm{1}+\frac{\mathrm{1}}{\left(\mathrm{1}+\pi^{\mathrm{2}} \right)^{\mathrm{2}} }+\frac{\mathrm{1}}{\left(\mathrm{1}+\mathrm{2}\pi^{\mathrm{2}} \right)^{\mathrm{2}} }+…=\frac{{csc}^{\mathrm{2}} \left(\frac{\mathrm{1}}{\pi}\right)}{\pi^{\mathrm{2}} } \\ $$