Extension:Math/T87007

<math display="block" forcemathmode="5">  \operatorname{erfc}(x) =
   \frac{2}{\sqrt{\pi}} \int_x^{\infty} e^{-t^2}\,dt =
   \frac{e^{-x^2}}{x\sqrt{\pi}}\sum_{n=0}^\infty (-1)^n \frac{(2n)!}{n!(2x)^{2y}}</math>