Loading ...
Sorry, an error occurred while loading the content.

Re: [PrimeNumbers] twin primes

Expand Messages
  • Phil Carmody
    ... Don t be fooled by the name, these only go up to 15 digits: http://www.meganumbers.com/ If you want anything larger, your best bet is to generate them
    Message 1 of 3 , Mar 5 1:05 AM
    • 0 Attachment
      On Sun, 04 March 2001, "�� ����" wrote:
      > who can give me a twin primes table below 1024 bits,or an address, thank you!

      Don't be fooled by the name, these only go up to 15 digits:
      http://www.meganumbers.com/

      If you want anything larger, your best bet is to generate them yourself.

      If you want twins in a particular contiguous range, and only need probable primes, then you probably ought to use OpenPFGW (see www.primeform.net) to probabilisticly test arbitrary numbers. You can follow up with a deterministic test using Titanix if you need them proved prime.
      However, if you are prepared to limit yourself to only "easy to prove" numbers, then you can get a deterministic test out of OpenPFGW. Chose a known factored part just greater than a third of the size of the number you wish to achieve. Primorials are a very good way of generating this known factored part if looking at compound (e.g. twin) primes.
      However, if you just need some twins fast, and are not using them for cryptographic purposes, your best bet is to chose a more restrictive range (i.e. far more of the number with known factors) and NewPGen as a prefilterer, using a 'primorial' search, and then use OpenPFGW to perform the probabilistic tests.

      All the links to the programs I've mentioned are on the prime pages: http://www.primepages.org/ under the section "prime links"

      Phil

      Hmmm - is there a FAQ answer to this?
      If not, shall we create one?



      >
      > Unsubscribe by an email to: primenumbers-unsubscribe@egroups.com
      > The Prime Pages : http://www.primepages.org
      >
      >
      >
      > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

      Mathematics should not have to involve martyrdom;
      Support Eric Weisstein, see http://mathworld.wolfram.com
      Find the best deals on the web at AltaVista Shopping!
      http://www.shopping.altavista.com
    • xordan_co
      Hola group: I am new here, this one is my first message. I have been reading the files of the group and I found the thread
      Message 2 of 3 , Mar 15 2:11 PM
      • 0 Attachment
        "Hola" group:

        I am new here, this one is my first message.

        I have been reading the files of the group and I found the thread
        http://tech.groups.yahoo.com/group/primenumbers/message/16551
        about prime twin numbers and the way of obtaining " infinite
        couples" of these numbers.

        I am the author of the sequences OEIS: A126193 and A126194. -

        I do not say that "infinites" pairs of twim primes could be obtained
        with this procedure;
        Y say that: with it, "many" twin primes can be obtained and in
        increasing sizes.
        I have wanted to try with the major couple of twin primes known to
        try to obtain others of major size, but my tools and knowledges are
        not sufficient.

        I propose this challenge to the group, probably someone could
        overcome the current record applying this procedure; the general
        form to obtain prime numbers with base in previous others appears in
        OEIS: A126769

        Xordan
        (Original in spanish, translation by software)
      Your message has been successfully submitted and would be delivered to recipients shortly.