\[\sum_{}^{} {n^s} = ?\]
직접 구하기
0에 대한 사실들
\[0^0\]
\[0!\]
\[x! (x<0)\]
\[(a+b)^n = \frac{n!}{(n-k)!k!}a^{n-k}b^k\]
\[\sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{{\pi}^{2}}{6}\]
\[\sum_{n=1}^{k} {a^n} = \frac{{a^{k+1}-1}}{a-1}\]
\[\sum_{n=a}^{b} {n} = \frac{(a+b)(b-a+1)}{2}\]
\[\sum_{n=a}^{b} {n^2} = \frac{(a-b)(2b^2 + 2ab + 3b +2a^2 + 3a +1)}{6}\]
\[\sum_{n=a}^{b} {n^2} = \frac{(a-b)(2b^2 + 2ab + 3b +2a^2 + 3a +1)}{6}\]