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Old 2020-12-16, 17:25   #19
kriesel
 
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Mar 2017
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Default Why don't we use 2 instead of 3 as the base for PRP or P-1 computations?

Mersenne numbers are base-2 pseudoprimes. All would be indicated as prime in P-1 factoring or Fermat PRP tests, whether actually prime or composite. Using 3 as the base provides useful information, and costs no more computing time; using 2 as the base provides no useful information. That's a summary of my understanding of this thread as it relates to base choice.


Top of this reference thread: https://www.mersenneforum.org/showth...736#post510736
Top of reference tree: https://www.mersenneforum.org/showpo...22&postcount=1

Last fiddled with by kriesel on 2020-12-17 at 16:41
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