1+1/3+1/5+1/7+.+1/(2n-1)=?

证明(1+2/n)^n>5-2/n（n属于N+,n>=3) 证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n 1 + (n + 1) + n*(n + 1) + n*n + (n + 1) + 1 = 2n^2 + 3n + 3 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? 3n²-n=1 求6n³+7n²-5n+2014 2^n/n*(n+1) (n+1)^n-(n-1)^n=? M=(N-1)×1+(N-2)×2+(N-3)×4+(N-4)×8+(N-5)×16+(N-6)×32+(N-7)×64 [3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简 若3n^2-n=1,求6n^3+7n^2-5n+2003的值 化简(n+1)(n+2)(n+3) 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)+··