Question Number 135143 by mnjuly1970 last updated on 10/Mar/21
$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:…..{nice}\:\:\:{calculus}… \\ $$$$\:\:\:\:\:\:\:\:{please}\:\:{calculate}:\downarrow\downarrow\downarrow \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\::::\:\:\boldsymbol{\phi}\overset{??} {=}\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{{H}_{{n}} ^{\:^{\mathrm{2}} } }{{n}^{\mathrm{2}} }\:\: \\ $$$$\:\:\:\:\:\: \\ $$
Commented by mnjuly1970 last updated on 10/Mar/21
$$\:\:{thank}\:{you}\:{mr}\:{payan}\:\: \\ $$$$\: \\ $$
Commented by Dwaipayan Shikari last updated on 10/Mar/21
$$\frac{\mathrm{17}\pi^{\mathrm{4}} }{\mathrm{360}} \\ $$
Commented by Dwaipayan Shikari last updated on 10/Mar/21
https://math.stackexchange.com/a/904248
I have found this here
Commented by mnjuly1970 last updated on 10/Mar/21
$$\:\:{thank}\:{you}\:{so}\:{much}\:{mr}\:{payan}.. \\ $$$$\:\: \\ $$