Question Number 226653 by MrAjder last updated on 09/Dec/25
$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\underset{{k}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\mathrm{Si}\left(\pi{n}\right)}{{n}^{\mathrm{2}} }=? \\ $$
Commented by Kassista last updated on 10/Dec/25
