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Old 2007-08-25, 12:14   #1
devarajkandadai
 
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minus A new sequence

A 132469 (OEIS) is a new sequence.
A.K.Devaraj
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Old 2007-08-25, 15:23   #2
Jens K Andersen
 
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A132469(n) = (2^(5n)-1)/31 = (32^n-1)/31 = base 32 generalized repunits.
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Old 2020-12-01, 21:23   #3
sweety439
 
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Quote:
Originally Posted by Jens K Andersen View Post
A132469(n) = (2^(5n)-1)/31 = (32^n-1)/31 = base 32 generalized repunits.
There are no primes in this sequence, since 32^n-1 = (2^n-1) * (16^n+8^n+4^n+2^n+1), and since the two factors are both >31 for n>5 ((32^n-1)/31 is not prime for all 1<=n<=5), thus the factorization is not trivial.
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Old 2020-12-01, 22:08   #4
VBCurtis
 
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You're only 13 years late, and not even on-topic.

https://en.wikipedia.org/wiki/Intern...m#Necroposting
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