化简16^n+2×4^n-1/8^2n×5^2n+4×2^n/5^2n+3×2^n+3
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n
化简:1/(n+1)(n+2)+1/(n+2)(n+3)+1/(n+3)(n+4)
一道数列求和题1/2n+3/4n+5/8n+...+(2n-1)/n*2^n
[3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简
lim 9^n+4^n+2/5^n-3^2n-1 n趋于无穷大时
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?
化简(n+1)(n+2)(n+3)
-n^3+8n^2-16n
(n+1)(n+2)/1 +(n+2)(n+3)/1 +(n+3)(n+4)/1
证明(1+2/n)^n>5-2/n(n属于N+,n>=3)
如果正整数n使得[n/2]+[n/3]+[n/4]+[n/5]+[n/6]=69,则n=
M=(N-1)×1+(N-2)×2+(N-3)×4+(N-4)×8+(N-5)×16+(N-6)×32+(N-7)×64