[seqfan] Re: (no subject)

Frank Adams-Watters franktaw at netscape.net
Thu Dec 7 04:13:01 CET 2017

A005109 includes primes of the  form 2^n + 1 (i.e., Fermat primes), while A058383 includes them.

I is the finitude of the Fermat primes that led to wonder about these.

Franklin T. Adams-Watters

-----Original Message-----
From: Allan Wechsler <acwacw at gmail.com>
To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
Sent: Wed, Dec 6, 2017 8:56 pm
Subject: [seqfan] Re: (no subject)

At the moment, I cannot reach OEIS. But coincidentally I ran into primes of
this class in a completely different context, only yesterday. Wikipedia, at
least, calls them "Pierpont primes", primes p such that p-1 is 3-smooth.
The article https://en.wikipedia.org/wiki/Pierpont_prime attributes to
Andrew Gleason the conjecture that there are infinitely many Pierpont
primes. Curiously, the article refers to the sequence A005109, not A058383;
I can't investigate this discrepancy until OEIS starts answering the phone
for me.

On Wed, Dec 6, 2017 at 1:45 PM, Hugo Pfoertner <yae9911 at gmail.com> wrote:
> In the range 1<=a,b<=500 there are 2111 primes of this form. Large
> examples: 1+(2^498)*(3^493) or 1+(2^994)*(3^993). Why should there be a
> limit?
>> Hugo Pfoertner>> On Wed, Dec 6, 2017 at 6:51 PM, Frank Adams-Watters via SeqFan <
> seqfan at list.seqfan.eu> wrote:>
> > Is https://oeis.org/A058383 (Primes of form 1+(2^a)*(3^b)) infinite?> >
> > Franklin T. Adams-Watters> >> >> > --> > Seqfan Mailing list - http://list.seqfan.eu

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