Originally Posted bydahamalian2000

RonL

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- February 4th 2006, 12:23 PM #1

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## please help!

hi, I am having trouble proving or disproving these two:

First:

If*p*is a prime number, must 2^p - 1 also be prime? Prove or give a counterexample.

Second:

If*n*is a nonnegative integer, must 2^(2^n) + 1 be prime? Prove of give a couterexample.

Thank you so much.

- February 4th 2006, 12:29 PM #2

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- February 4th 2006, 12:34 PM #3

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- February 4th 2006, 01:05 PM #4

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- February 4th 2006, 01:32 PM #5

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- February 4th 2006, 02:37 PM #6

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