Question Number 33887 by math khazana by abdo last updated on 26/Apr/18
$${find}\:{the}\:{value}\:{of}\:\sum_{{n}=\mathrm{0}} ^{\infty} \:\:\frac{\left(−\mathrm{1}\right)^{{n}} }{\mathrm{4}{n}+\mathrm{1}}\:. \\ $$
find-the-value-of-n-0-1-n-4n-1-