(2*4*6*8*.*2n)/(1*3*5*7*9*.*)=?
M=(N-1)×1+(N-2)×2+(N-3)×4+(N-4)×8+(N-5)×16+(N-6)×32+(N-7)×64
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?
已知888个连续正整数之和:n+(n+1)+(n+2)+(n+3)+(n+4)+(n+5)+(n+6)+(n+7)+··
简算:[(1*2*4+2*4*8+L+n.2n.4n)/(1*3*9+2*6*18+L=n.3n.9n)]^2
简算:1.[(1*2*4+2*4*8+L+n.2n.4n)/(1*3*9+2*6*18+L=n.3n.9n)]^22.(
如果正整数n使得[n/2]+[n/3]+[n/4]+[n/5]+[n/6]=69,则n=
1\n(n+3)+1\(n+3)(n+6)+1\(n+6)(n+9)=1\2 n+18 n为正整数,求n的值
lim 9^n+4^n+2/5^n-3^2n-1 n趋于无穷大时
16n^a+4n^3+6n^2+7^n=0,求n
如果正整数n使得[n/2]+[n/3]+[n/4]+[n/5]+[n/6]=69,则n为( ).([ n ]表示不超过n
若3n^2-n=1,求6n^3+7n^2-5n+2003的值
一道数列求和题1/2n+3/4n+5/8n+...+(2n-1)/n*2^n