Question Number 22435 by Tinkutara last updated on 18/Oct/17
$${C}_{\mathrm{0}} \:^{\mathrm{2}{n}} {C}_{{n}} −{C}_{\mathrm{1}} \:^{\mathrm{2}{n}−\mathrm{2}} {C}_{{n}} +{C}_{\mathrm{2}} \:^{\mathrm{2}{n}−\mathrm{4}} {C}_{{n}} \:…. \\ $$$$\mathrm{equals}\:\mathrm{to} \\ $$