# [seqfan] Re: Composite numbers n such that digits of prime factors of n are either 4 or 9.

David Corneth davidacorneth at gmail.com
Wed Sep 23 09:41:56 CEST 2020

```Thanks both. I really like that idea Robert. Maximilian and I talked a bit
about it and he'll make a stub and that helps so I know where to put it and
such. Then I'll try to dig up a bunch of those sequences. I just saw
another part of that family being edited/created. If I understand the idea
of an entry correctly then that sounds good to me too.

Best,
David

On Tue, Sep 22, 2020 at 6:28 PM <israel at math.ubc.ca> wrote:

> More generally, for every list S of primes we could have a sequence for
> "Composite numbers whose prime factors are in S".  There are lots of those!
>
> Cheers,
> Robert
>
>
> On Sep 22 2020, Neil Sloane wrote:
>
> >D Corneth said:
> >
> >There's no wiki for that family (right?). Do I add the 24
> >sequences as an xref or would we (an expert on that) make a new
> >wikipage for it?
> >
> >Me:  The best thing: make an entry for this in the OEIS Index, and add
> >links to the Index entry from each of the sequences
> >
> >I don't think we need yet another wiki page
> >
> >
> >Best regards
> >Neil
> >
> >Neil J. A. Sloane, President, OEIS Foundation.
> >11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
> >Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
> >Email: njasloane at gmail.com
> >
> >
> >
> >On Tue, Sep 22, 2020 at 11:19 AM David Corneth <davidacorneth at gmail.com>
> >wrote:
> >
> >> I'm now editing "Composite numbers n such that digits of prime factors
> >> of n are either 4 or 9." (A036319) which is a member of a family of at
> >> least 24 sequences. There's no wiki for that family (right?). Do I add
> >> the 24 sequences as an xref or would we (an expert on that) make a new
> >> wikipage for it?
> >>
> >> Best,
> >> David
> >>
> >> --
> >> Seqfan Mailing list - http://list.seqfan.eu/
> >>
> >
> >--
> >Seqfan Mailing list - http://list.seqfan.eu/
> >
> >
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>

```