1+1!+2+2!+3+3!+……+n+n!

(1/(n^2 n 1 ) 2/(n^2 n 2) 3/(n^2 n 3) ……n/(n^2 n n)) 当N越于无穷大 证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n 用数学归纳法证明：1×2×3+2×3×4+…+n×(n+1)×(n+2)＝n(n+1)(n+2)(n+3)4(n∈N 求极限Xn=n/(n^2+1)+n/(n^2+2)+n/(n^2+3)+……+n/(n^2+n), 证明1/(n+1)+1/(n+2)+1/(n+3)+……+1/(n+n) lim(1/n^2+4/n^2+7/n^2+…+3n-1/n^2) VB编程n!+(n+1)!+(n+2)!+(n+3)!+……+(n+m)! 计算：C(1,n)+2C(2,n)+3C(3,n) + … + nC(n,n) 用数学归纳法证明：（n+1）+（n+2）+…+（n+n）=n(3n+1)2 n是自然数,0≤n≤101,则| n-1|+|n-2|+|n-3|+…+|n-100|的最小值, 如果,n是大于2的整数,计算1/(n-1)(n-2)+1/(n-2)(n-3)+1/(n-3)(n-4)+……+1/(n f(n)=1/(n+1)+1/(n+2)+1/(n+3)……+1/2n (n∈N*),f(n+1