Question Number 136325 by frc2crc last updated on 20/Mar/21
$${please}\:{a}\:{generall}\:{Form}\:{for}\:{C}\left({n}\right) \\ $$$${C}\left({n}\right)=\frac{\mathrm{4}}{\pi^{\mathrm{2}} }\underset{{k}=\mathrm{1}} {\overset{{n}} {\sum}}\left(−\mathrm{1}\right)^{{k}−\mathrm{1}} \zeta\left(\mathrm{2}{k}\right)\zeta\left(\mathrm{2}{n}−\mathrm{2}{k}\right) \\ $$
Commented by Dwaipayan Shikari last updated on 20/Mar/21
$${C}\left(\mathrm{1}\right)\rightarrow{Diverges} \\ $$$${C}\left(\mathrm{2}\right)\rightarrow{Diverges} \\ $$$${C}\left(\mathrm{3}\right)\rightarrow{Diverges}\: \\ $$$$.. \\ $$$${No}\:{such}\:{General}\:{form}.. \\ $$