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Old 2019-11-23, 22:39   #6
sweety439
 
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"99(4^34019)99 palind"
Nov 2016
(P^81993)SZ base 36

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Quote:
Originally Posted by a1call View Post
The Mersenne part has been known since 1775 as proven in this link first shown to me by sm:
https://primes.utm.edu/notes/proofs/MerDiv2.html
It is of practical use in proving factors of Mersenne numbers with prime exponents prime.
23 is guaranteed to be prime because it divides M11 and 23= 2*11+1
341 divides M170 and 341=2*170+1, but 341 is not prime
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