求证1*n+2*(n-1)+3*(n-2)+…+n*1=1/6n(n+1)(n+2)
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n
2^n/n*(n+1)
当n为正偶数,求证n/(n-1)+n(n-2)/(n-1)(n-3)+...+n(n-2).2/(n-1)(n-3)..
[3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简
设n∈N,n>1.求证:logn (n+1)>log(n+1) (n+2)
求证:C(0,n)+2C(1,n)+.+(n+1)C(n,n)=2^n+2^(n-1)
(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
Sn=n(n+2)(n+4)的分项等于1/6[n(n+2)(n+4)(n+5)-(n-1)n(n+2)(n+4)]吗?
1 + (n + 1) + n*(n + 1) + n*n + (n + 1) + 1 = 2n^2 + 3n + 3
数学定理证明求证2^n-1=2^n-1+2^n-2+2^n-3+.+2^n-n
求证c(n,1)+2c(n,2)+3c(n,3)+...+nc(n,n)=n2^(n-1)
请教初一的数学题急求证:N=52*32n+1*2n-3n*3n*6n+2能被13整除.2 2n+1 n n n n+2分