[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

Frank Adams-Watters franktaw at netscape.net
Tue Nov 25 23:02:45 CET 2014


The PARI program in A075321 does not work.

Franklin T. Adams-Watters

-----Original Message-----
From: Charles Greathouse <charles.greathouse at case.edu>
To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
Sent: Tue, Nov 25, 2014 2:13 pm
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


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
> > >
> > > _______________________________________________
> > >
> > > Seqfan Mailing list - http://list.seqfan.eu/
> > >
>
> > _______________________________________________
>
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