(sum_{i=1}^ni=frac{n(n+1)}{2})
(sum_{i=1}^ni^2=frac{n(n+1)(2n+1)}{6})
(sum_{i=1}^ni^3=frac{n^2(n+1)^2}{4})
(sum_{i=1}^{n}i^4=frac{n(n+1)(2n+1)(3n^2+3n-1)}{30})
(sum_{i=1}^ni=frac{n(n+1)}{2})
(sum_{i=1}^ni^2=frac{n(n+1)(2n+1)}{6})
(sum_{i=1}^ni^3=frac{n^2(n+1)^2}{4})
(sum_{i=1}^{n}i^4=frac{n(n+1)(2n+1)(3n^2+3n-1)}{30})