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-   -   A new sequence (https://www.mersenneforum.org/showthread.php?t=9111)

devarajkandadai 2007-08-25 12:14

A new sequence
 
A 132469 (OEIS) is a new sequence.
A.K.Devaraj

Jens K Andersen 2007-08-25 15:23

[URL="http://www.research.att.com/~njas/sequences/A132469"]A132469[/URL](n) = (2^(5n)-1)/31 = (32^n-1)/31 = base 32 [URL="http://primes.utm.edu/glossary/page.php?sort=GeneralizedRepunit"]generalized repunits[/URL].

sweety439 2020-12-01 21:23

[QUOTE=Jens K Andersen;112987][URL="http://www.research.att.com/~njas/sequences/A132469"]A132469[/URL](n) = (2^(5n)-1)/31 = (32^n-1)/31 = base 32 [URL="http://primes.utm.edu/glossary/page.php?sort=GeneralizedRepunit"]generalized repunits[/URL].[/QUOTE]

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.

VBCurtis 2020-12-01 22:08

You're only 13 years late, and not even on-topic.

[url]https://en.wikipedia.org/wiki/Internet_forum#Necroposting[/url]


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