Question Number 86592 by M±th+et£s last updated on 29/Mar/20
$${prove}\:{that} \\ $$$$\mathrm{2}\underset{{x}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\mathrm{2}^{{x}} \:\left({x}!\right)^{\mathrm{2}} }{\left(\mathrm{2}{x}\right)!\:\left({x}\right)} \\ $$
Commented by M±th+et£s last updated on 29/Mar/20
$$=\pi \\ $$