[seqfan] Re: Numbers such that the n-th and (n+1)st terms are the successors of prime numbers and primes themselves and n+1 > n

Neil Sloane njasloane at gmail.com
Tue Nov 25 22:05:52 CET 2014


Yep, that worried me too. unkn,obsc,uned would
seem to take care of it

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.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com


On Tue, Nov 25, 2014 at 3:12 PM, Charles Greathouse <
charles.greathouse at case.edu> wrote:

> Indeed, it was just this sort of discrepancy that alerted me to the
> problem, since A147513 contains 51 = 3*17.
>
> Charles Greathouse
> Analyst/Programmer
> Case Western Reserve University
>
> On Tue, Nov 25, 2014 at 2:26 PM, David Applegate <david at research.att.com>
> wrote:
>
> > While poking around at this, I came across A075321,A075322, and A075323.
> > These are based on "pair the odd primes so that the k-th pair is (p,
> p+2k)"
> > The three sequences are the first in the pair, the second in the pair,
> and
> > the pairs in order.
> >
> > As I read the description, every term should be prime.  However, when I
> > look
> > at the sequence, I see 45, 55, 99, 115, 169, 201, 235, all of which are
> > composite.  Are the sequences wrong, or does the definition need to be
> > cleaned
> > up?
> >
> > -Dave
> >
> > > From seqfan-bounces at list.seqfan.eu Tue Nov 25 13:51:54 2014
> > > Date: Tue, 25 Nov 2014 13:50:58 -0500
> > > From: Neil Sloane <njasloane at gmail.com>
> > > To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
> > > Subject: [seqfan] Re: Numbers such that the n-th and (n+1)st terms are
> > the  successors of prime numbers and primes themselves and n+1 > n
> >
> > > That one (A147513) is certainly a mess.  If no one has a better idea,
> > let's
> > > leave the terms intact, but give it keywords uned,obsc,unkn !
> >
> > > 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.
> > > Phone: 732 828 6098; home page: http://NeilSloane.com
> > > Email: njasloane at gmail.com
> >
> > > On Tue, Nov 25, 2014 at 1:30 PM, Charles Greathouse <
> > > charles.greathouse at case.edu> wrote:
> >
> > > > Does anyone understand the definition of A147513? The terms start
> > > > 3, 5, 7, 11, 13, 19, 23, 31, 37, 47, 51
> > > > and no other information is given.
> > > >
> > > > Charles Greathouse
> > > > Analyst/Programmer
> > > > Case Western Reserve University
> > > >
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