I try for infinite n

P(notE)=1/2^2+1/3^2+1/5^2+...

        -1/2^2*1/3^2-1/2^2*1/5^2-...

        +1/2^2*1/3^2*1/5^2+....

        -........

P(E)=1-P(notE),the limit, I quess ,is open question.

所有跟帖： 

• 6 / π^2 。 -guest007- ♀ (901 bytes) () 10/22/2010 postreply 10:26:28

• Thanks, 6 / π^2 is the limit. I think is right. -jinjing- ♀ (37 bytes) () 10/22/2010 postreply 10:47:16

• 回複：6 / π^2 。 -o=o- ♂ (312 bytes) () 10/24/2010 postreply 23:14:22