(2^n+1)/3
Gottfried Helms
Annette.Warlich at t-online.de
Mon May 23 20:20:36 CEST 2005
Am 20.05.05 08:50 schrieb kohmoto:
>
> Hello, Seqfans
> Once I realized that if M_n is a Mersenne prime then (M_n+2)/3 is
> also prime. 2<n
> And I knew that it is called "Bateman and Shefridge and Wagstaff's
> conjecture ".
> Does anyone know the exact description of it?
>
> %I A000001
> %S A000001 3, 11, 43, 2731, 43691
> %N A000001 (M_n+2)/3. Where M_n is Mersenne prime 2^n-1.
> %C A000001 If "Bateman and Shefridge and Wagstaff's conjecture " is
> true, then all terms of the sequence becomes primes.
> %O A000001 3,1
> %Y A000001 A000668
> %K A000001 nonn
> %A A000001 Yasutoshi Kohmoto (zbi74583 at boat.zero.ad.jp)
>
>
>
Hi Yasutoshi -
I apologize for my previous postings, they were not much helpful
and may have seem to be not focused to your question, when I reread
them again.
What I was trying was to be helpful with a line of arguments,
which were related to
http://www.research.att.com/cgi-bin/access.cgi/as/njas/sequences/eisA.cgi?Anum=A007733
the sequence of the residues of n'th powers of 2 (modulo n) , which seemed
promising.
On the net a few days ago I found a fully explicite discussion of
that idea, applied to some number-theory-problems in the same manner, as I
tried to develop recently.
see http://www.dybot.com/numbers/sqfree.htm
Unfortunately, this path does actually *not* give a decisive help to get
nearer to a confirmation or disconfirmation of your observation,- conversely
your (resp. the Batesman-et-al-) conjecture is independent to the current
observations which were made when applying and analyzing that (unfortunately
incomplete) apparatus:
it is equivalent to a question whether unique *even* cycle-lengthes exist,
(which are also connected to mersenne-primes).
Nearly all that relevant observations and current assumptions still need
rigid proofs, so that optimistic postings of mine were also misleading.
Kind regards -
Gottfried Helms
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