n!=\Gamma(n+1)=\left(\frac{n}{e}\right)^n \sqrt{2\pi n}\left(1+\frac{1}{12n} + \frac{1}{288n^2}-\frac{139}{51840n^3}-\frac{571}{2488320n^4}+\frac{O(1)}{n^5}\right)