几个i的幂的累加公式1^2+2^2+3^2 2~5

1^2+2^2+3^2+……+n^2=n(n+1)(2n+1)/6

1^3+2^3+3^3+...+n^3=(1+2+3+...+n)^{^2} =[n(n+1)/2]^{^2}

1^4+2^4+3^4+……+n^4=n(n+1)(2n+1)(3n²+3n-1)/30.

1^5+2^5+3^5+……+n^5=n^{^2}(n+1)^2(2n²+2n-1)/12.