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Topic: Combining Primes
Replies: 81   Last Post: Aug 19, 2013 1:12 PM

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Peter Percival

Posts: 2,623
Registered: 10/25/10
Re: Combining Primes
Posted: Aug 10, 2013 3:33 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Virgil wrote:
> In article <pan.2013.08.10.15.23.49@jimkeener.com>,
> jim <jim@jimkeener.com> wrote:
>

>> Is there any way to combine 2 primes to get a larger prime, either
>> guarantying the primality of the result or with a quick test for the
>> primality?
>>
>> Thanks,
>> Jim

>
> The only time that the sum of two primes is also a prime is when their
> difference is 2 in such "twin primes" as 5 and 7 or 17 and 19 or 41 and
> 43.
>
> http://en.wikipedia.org/wiki/Twin_prime


Leaving aside the prime 2, the sum of two primes is even and thus
divisible by two. Clearly I'm missing something.

--
Nam Nguyen in sci.logic in the thread 'Q on incompleteness proof'
on 16/07/2013 at 02:16: "there can be such a group where informally
it's impossible to know the truth value of the abelian expression
Axy[x + y = y + x]".


Date Subject Author
8/10/13
Read Combining Primes
jim
8/10/13
Read Re: Combining Primes
namducnguyen
8/10/13
Read Re: Combining Primes
namducnguyen
8/10/13
Read Re: Combining Primes
Sandy
8/10/13
Read Re: Combining Primes
namducnguyen
8/10/13
Read Re: Combining Primes
Sandy
8/10/13
Read Re: Combining Primes
namducnguyen
8/10/13
Read Re: Combining Primes
Sandy
8/10/13
Read Re: Combining Primes
Bart Goddard
8/10/13
Read Re: Combining Primes
Peter Percival
8/10/13
Read Re: Combining Primes
Bart Goddard
8/11/13
Read Re: Combining Primes
Peter Percival
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Bart Goddard
8/11/13
Read Re: Combining Primes
Peter Percival
8/11/13
Read Re: Combining Primes
fom
8/10/13
Read Re: Combining Primes
antani
8/10/13
Read Re: Combining Primes
Bart Goddard
8/10/13
Read Re: Combining Primes
namducnguyen
8/10/13
Read Re: Combining Primes
Bart Goddard
8/10/13
Read Re: Combining Primes
namducnguyen
8/10/13
Read Re: Combining Primes
Bart Goddard
8/10/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Peter Percival
8/11/13
Read Re: Combining Primes
namducnguyen
8/10/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Peter Percival
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Peter Percival
8/10/13
Read Re: Combining Primes
Virgil
8/10/13
Read Re: Combining Primes
Peter Percival
8/10/13
Read Re: Combining Primes
rossum
8/10/13
Read Re: Combining Primes
John
8/10/13
Read Re: Combining Primes
Helmut Richter
8/10/13
Read Re: Combining Primes
Helmut Richter
8/19/13
Read Re: Combining Primes
Phil Carmody
8/10/13
Read Re: Combining Primes
antani
8/11/13
Read Re: Combining Primes
Helmut Richter
8/10/13
Read Re: Combining Primes
Sandy
8/10/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Sandy
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Sandy
8/10/13
Read Re: Combining Primes
William Elliot
8/10/13
Read Re: Combining Primes
namducnguyen
8/10/13
Read Re: Combining Primes
William Elliot
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
William Elliot
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
William Elliot
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Sandy
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Sandy
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Sandy
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Sandy
8/11/13
Read Re: Combining Primes
namducnguyen
8/12/13
Read Re: Combining Primes
Sandy
8/12/13
Read Re: Combining Primes
Bart Goddard
8/13/13
Read Re: Combining Primes
Shmuel (Seymour J.) Metz
8/11/13
Read Re: Combining Primes
Sandy
8/19/13
Read Re: Combining Primes
Phil Carmody
8/11/13
Read Re: Combining Primes
Sandy
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
Sandy
8/13/13
Read Re: Combining Primes
Shmuel (Seymour J.) Metz
8/11/13
Read Re: Combining Primes
Pubkeybreaker
8/11/13
Read Re: Combining Primes
Peter Percival
8/11/13
Read Re: Combining Primes
fom
8/11/13
Read Re: Combining Primes
Brian Q. Hutchings
8/12/13
Read Re: Combining Primes
namducnguyen
8/12/13
Read Re: Combining Primes
namducnguyen
8/12/13
Read Re: Combining Primes
Peter Percival
8/13/13
Read Re: Combining Primes
Shmuel (Seymour J.) Metz
8/12/13
Read Re: Combining Primes
Peter Percival
8/11/13
Read Re: Combining Primes
namducnguyen
8/11/13
Read Re: Combining Primes
namducnguyen
8/12/13
Read Re: Combining Primes
namducnguyen
8/12/13
Read Re: Combining Primes
Peter Percival
8/19/13
Read Re: Combining Primes
Phil Carmody

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