for every positive even interger n, the function h(n) is defined to be the product of all the even intergers from 2 to n. if p is the smallest prime factor of h(100) +1, then p is
a. between 2 and 10
b. between 10 and 20
c. between 20 and 30
d. between 30 and 40
e. over 40作者: LuckyStars 时间: 2012-8-30 20:44
h(n)=2*4*6*8*....*100 +1
=2^50 *(1*2*3*...*50)+1
因为p is the smallest prime factor of h(100)+1，而2^50 *(1*2*3*...*50) 中的prime由于有后面的1*...*50已经大于50了
所以选E作者: nesstang 时间: 2012-8-31 06:39
