(n+1)^n-(n-1)^n=?
(n+1)^n-(n-1)^n=?
证明n^n-n(n-a)^(n-1)>=n!a.其中n>=a>0
证明:(n+1)n!= (n+1)!
2^n/n*(n+1)
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n
阶乘(2n-1)!=(2n)!/(2^n*n!
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?
for(n=1;n
1 + (n + 1) + n*(n + 1) + n*n + (n + 1) + 1 = 2n^2 + 3n + 3
A(n,n)+A(n-1,n-1)=XA(n+1,n+1)
判断级数敛散性∑(n=1到∞)(n+1/n)/(n+1/n)^n
{[(n+1)^(n+1)]/(n+1)!}*[n!/(n^n)]=?请高手赐教,最好写出步骤,