Question Number 130415 by Dwaipayan Shikari last updated on 25/Jan/21
$$\frac{\pi}{{e}}{sin}\left(\mathrm{1}\right)−\frac{\pi^{\mathrm{2}} }{\mathrm{2}{e}^{\mathrm{2}} }{sin}\left(\mathrm{2}\right)+\frac{\pi^{\mathrm{3}} }{\mathrm{3}{e}^{\mathrm{3}} }{sin}\left(\mathrm{3}\right)−\frac{\pi^{\mathrm{4}} }{\mathrm{4}{e}^{\mathrm{4}} }{sin}\left(\mathrm{4}\right)+… \\ $$
Commented by Dwaipayan Shikari last updated on 25/Jan/21
$${tan}^{−\mathrm{1}} \left(\frac{\pi{sin}\left(\mathrm{1}\right)}{\pi{cos}\left(\mathrm{1}\right)+{e}}\right) \\ $$$${But}\:{i}\:{am}\:{not}\:{sure} \\ $$