# [seqfan] Re: A124240 = n's where (p-1)|n for all primes p|n?

David Wilson davidwwilson at comcast.net
Tue Aug 27 05:01:49 CEST 2013

```I would venture that

a_f = n such that p | n => f(p) | n

where polynomial f that factors into monomials with rational coefficients,
is an infinite sequence.

A124240 = a_f where f(p) = p-1.

Also interesting are a_f where f(p) = p+1 or f(p) = p^2-1.

> -----Original Message-----
> From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of Max
> Alekseyev
> Sent: Sunday, August 25, 2013 11:20 AM
> To: Leroy Quet
> Cc: Leroy Quet; Sequence Fanatics Discussion list
> Subject: [seqfan] Re: A124240 = n's where (p-1)|n for all primes p|n?
>
> This trivially follows from the formula for A002322(n). And initial 1 is
not an
> exception here.
> I've made the corresponding corrections to A124240.
> Regards,
> Max
>
> On Fri, Jun 27, 2008 at 12:45 PM, Leroy Quet <q1qq2qqq3qqqq at yahoo.com>
> wrote:
> > Does sequence A124240, with the possible exception of the initial 1,
also
> equal the sequence of those positive integers n where (p-1) divides n for
all
> primes p that divide n?
> >
> > Thanks,
> > Leroy Quet
> >
> >
> >
> >
> >
> >
> >
>
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```