# [seqfan] Re: Triples of 3-digit primes using together digits 1..9.

zak seidov zakseidov at yahoo.com
Thu Jul 8 03:38:19 CEST 2010

```
--- On Wed, 7/7/10, Ray Chandler <rayjchandler at sbcglobal.net> wrote:

> From: Ray Chandler <rayjchandler at sbcglobal.net>
> Subject: [seqfan] Re: Triples of 3-digit primes using together digits 1..9.
> To: "'Sequence Fanatics Discussion list'" <seqfan at list.seqfan.eu>
> Date: Wednesday, July 7, 2010, 4:45 PM
> I believe Zak counted the ordered
> triples (p1<p2<p3) whereas Harvey's code
> counts triples without regard for order.

Me: Yes!
>
> I would expect Harvey's number to 6 times Zak's number, and
> it is.

Me: Yes!

Q Can anyone find sudoku sokution with all
triples prime?
Zak
> Ray
>
> > -----Original Message-----
> > From: seqfan-bounces at list.seqfan.eu
>
> > [mailto:seqfan-bounces at list.seqfan.eu]
> On Behalf Of Harvey P. Dale
> > Sent: Wednesday, July 07, 2010 2:28 PM
> > To: Sequence Fanatics Discussion list
> > Subject: [seqfan] Re: Triples of 3-digit primes using
>
> > together digits 1..9.
> >
> > Zak:
> >
> >     I think there are 816 such
> triples.  This Mathematica
> > program will generate them in the form of 9-digit
> numbers.
> >
> > okQ[n_] :=
> >  Module[{idn = FromDigits /@
> Partition[IntegerDigits[n], 3]},
> >   PrimeQ[idn[[1]]] &&
> PrimeQ[idn[[2]]] && PrimeQ[idn[[3]]]]
> > Select[FromDigits /@ Permutations[Range[9]], okQ]
> >
> >     Best,
> >
> >     Harvey
> >
> > -----Original Message-----
> > From: seqfan-bounces at list.seqfan.eu
> > [mailto:seqfan-bounces at list.seqfan.eu]
> On Behalf Of zak seidov
> > Sent: Tuesday, July 06, 2010 10:24 AM
> > To: seqfaneu
> > Subject: [seqfan] Triples of 3-digit primes using
> together
> > digits 1..9.
> >
> > Triples of 3-digit primes,
> > using together digits 1..9.
> > There are 136 such triples,
> > from {127,463,859} to {659,743,821}.
> >
> > http://zak08.livejournal.com/23029.html
> >
>
>
>
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>
> Seqfan Mailing list - http://list.seqfan.eu/
>

```