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Does it continue? 5: powers of 2 (Posted on 2017-09-24) Difficulty: 3 of 5
Before trying the problem "note your opinion as to whether the observed pattern is known to continue, known not to continue, or not known at all."

For integers greater than 1,
2n is never congruent to 1 (mod n)
2n is congruent to 2 (mod n) whenever n is prime, and sometimes when it isn't,
is 2n ever congruent to 3 (mod n)?

No Solution Yet Submitted by Jer    
Rating: 5.0000 (1 votes)

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The question | Comment 5 of 6 |
I appreciate the insights.  There is only one question here, the first two are statements.
It seemed trivial that it would never be 1, and always 2 for primes.  The trick here was that finding 3 would likely elude computer solvers.

I didn't realize the problem was already on the site from 2008, so this is a repeat.  However, you folks took the problem further than before, so that's cool.

  Posted by Jer on 2017-09-25 10:53:13
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