For how many integer values of *i*, 1 ≤ *i* ≤ 1000, does there exist an integer *j*, 1 ≤ *j* ≤ 1000, such that *i* is a divisor of 2^{ j } − 1?

is a prime number for *n* = odd .

In the range [1, 1000], there are 1000 numbers out of which 500 are even and 500 are odd.

So, for all odd values of *i,* is divisible by *i.*

Thus, the number of values are 500.

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