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

pfgw reporting a CPAP-4 that is

Expand Messages
  • Ken Davis
    Hi all, Third time lucky 2^5900 + 469721931951 2^5900 + 469721934831 2^5900 + 469721937711 2^5900 + 469721940591 form a CPAP4 each with 1777 digits and
    Message 1 of 10 , Nov 12, 2007
      Hi all,

      Third time lucky
      2^5900 + 469721931951
      2^5900 + 469721934831
      2^5900 + 469721937711
      2^5900 + 469721940591

      form a CPAP4 each with 1777 digits and difference 2880

      Cheers
      Ken
      --- In primeform@yahoogroups.com, "Ken Davis" <kradenken@...> wrote:
      >
      > Hi Jim,
      > Having thought about it over the lt couple of days I had come to
      the
      > same conclusion.
      > The prp testing is fine and the original sieving wasn't by pfgw.
      > I hv ealreadyhad 123 AP-3's of which 113 were reported as CPAP-3. I
      > never bothered verifying them as it was an AP4 I am searching for.
      > I'l continue on then
      > Thanks
      > Ken
      >
      > --- In primeform@yahoogroups.com, "jim_fougeron" <jfoug@> wrote:
      > >
      > > I have started looking into the cpap format (the JF CPAP-??
      format)
      > > file processing.
      > >
      > > What is happening, is that "internally", the program (once it
      finds
      > a
      > > AP of probable size), it quickly performs a pretty shallow (first
      > 10k
      > > primes) window'd SoE over the range (tracking which factors are
      > > found), and on the candidates left, it performs a PRP test. If
      > none
      > > of these PRP test result in a PRP, then it is written out as a
      CPAP
      > > result.
      > >
      > > However, the code doing the SoE is totally broken (as listed by
      > > Jens). I do not know if/when this code was working, but it is
      > > obviously broken.
      > >
      > > However, all of the "found" AP's are still valid. It is just the
      > > verification that is busted. Thus, if you have other AP's found,
      > > they are valid. If there are no other AP-4's found, then there
      > were
      > > no others in your test data. Thus, there are no missed AP's,
      > > just "falsely" listed CPAP's.
      > >
      > > Jim.
      > >
      > >
      > > --- In primeform@yahoogroups.com, "Jens Kruse Andersen"
      > > <jens.k.a@> wrote:
      > > >
      > > > Ken Davis wrote:
      > > > > pfgw cpap4.in -lcpap4.log
      > > > > with cpap.in =
      > > > >
      > > > > JF CPAP-5 2^5900
      > > > > 172518140307 3150
      > > >
      > > > I have no previous experience with the JF format and have not
      > seen
      > > > it documented. I don't know how to fix it but will just observe
      > > what
      > > > goes wrong using PFGW 1.2.0.
      > > >
      > > > I made cpap4abc.in with this:
      > > > ABC2 2^5900+172518140307+$a
      > > > a:from 0 to 9450 step 2
      > > >
      > > > pfgw -f cpap4abc.in -lcpap4abc.log
      > > > gives this in cpap4abc.log (factors verified by PARI/GP):
      > > > 2^5900+172518140307+2398 is 3-PRP! (0.1490s+0.0554s)
      > > > 2^5900+172518140307+2400 has factors: 127
      > > > 2^5900+172518140307+2402 has factors: 3
      > > > 2^5900+172518140307+2404 is composite: [57EBE58EC2D21DD]
      > > (0.1374s+0.0701s)
      > > > ...
      > > > 2^5900+172518140307+2422 has factors: 5
      > > > 2^5900+172518140307+2424 is composite: [160E5E697CE17556]
      > > (0.1350s+0.0593s)
      > > > 2^5900+172518140307+2426 has factors: 3
      > > > 2^5900+172518140307+2428 is 3-PRP! (0.1349s+0.0514s)
      > > >
      > > > cpap4.log from Ken's JF file has very different content:
      > > > 2^5900+172518140307+2398 has factors: 5
      > > > 2^5900+172518140307+2400 has factors: 3
      > > > 2^5900+172518140307+2402 is composite: [2EDEDA40E91BFEED]
      > > (0.1378s+0.0031s)
      > > > 2^5900+172518140307+2404 is composite: [57EBE58EC2D21DD]
      > > (0.1415s+0.0005s)
      > > > ...
      > > > 2^5900+172518140307+2422 has factors: 14747
      > > > 2^5900+172518140307+2424 has factors: 3
      > > > 2^5900+172518140307+2426 has factors: 17
      > > > 2^5900+172518140307+2428 has factors: 5
      > > >
      > > > So trial factoring went completely wrong with the JF format.
      > > > It found false factors and overlooked real factors.
      > > >
      > > > --
      > > > Jens Kruse Andersen
      > > >
      > >
      >
    • Jens Kruse Andersen
      ... Congratulations! http://hjem.get2net.dk/jka/math/cpap.htm is updated with the first proven CPAP record since March 2005. -- Jens Kruse Andersen
      Message 2 of 10 , Nov 12, 2007
        Ken Davis wrote:
        > 2^5900 + 469721931951
        > 2^5900 + 469721934831
        > 2^5900 + 469721937711
        > 2^5900 + 469721940591
        >
        > form a CPAP4 each with 1777 digits and difference 2880

        Congratulations!
        http://hjem.get2net.dk/jka/math/cpap.htm is updated with
        the first proven CPAP record since March 2005.

        --
        Jens Kruse Andersen
      • Ken Davis
        Hi Jens, I think it also qualifies for largest differnce for a CPAP4 also cheers Ken
        Message 3 of 10 , Nov 12, 2007
          Hi Jens,
          I think it also qualifies for largest differnce for a CPAP4 also
          cheers
          Ken

          --- In primeform@yahoogroups.com, "Jens Kruse Andersen"
          <jens.k.a@...> wrote:
          >
          > Ken Davis wrote:
          > > 2^5900 + 469721931951
          > > 2^5900 + 469721934831
          > > 2^5900 + 469721937711
          > > 2^5900 + 469721940591
          > >
          > > form a CPAP4 each with 1777 digits and difference 2880
          >
          > Congratulations!
          > http://hjem.get2net.dk/jka/math/cpap.htm is updated with
          > the first proven CPAP record since March 2005.
          >
          > --
          > Jens Kruse Andersen
          >
        • Jens Kruse Andersen
          ... Right! Thanks for pointing that out. The record page is updated. -- Jens Kruse Andersen
          Message 4 of 10 , Nov 13, 2007
            Ken Davis wrote:
            >> > form a CPAP4 each with 1777 digits and difference 2880
            > I think it also qualifies for largest differnce for a CPAP4 also

            Right! Thanks for pointing that out. The record page is updated.

            --
            Jens Kruse Andersen
          Your message has been successfully submitted and would be delivered to recipients shortly.