If(2^a -1) divides (2^{a(b-1)} + 2^{a(b-2)} + ... + 2^2a + 2^a + 1)

for a, b 2^a - 1 and 2^b -1 being odd primes

What does it tell us about b?

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- Nov 21st 2010, 02:02 PM #1

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- Nov 21st 2010, 02:15 PM #2

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