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Re: Some drag-racing progress...

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  • robert44444uk
    ... Phil A further advance, on the Riesel side, just failing at 75 primes: 74 972 147707435198851 R 52
    Message 1 of 10 , Dec 14, 2011
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      --- In primenumbers@yahoogroups.com, Phil Carmody <thefatphil@...> wrote:
      >
      > --- On Thu, 10/27/11, robert44444uk <robert_smith44@...> wrote:
      > > Phil Carmody <thefatphil@> wrote:
      > > > Firstly, Jack, can you update Carlos Rivera with your target values,
      > > > otherwise we don't know exactly what we're trying to beat!
      > > >
      > > > In response to Jack's "Any of these milestones are exceptional", with
      > > > reference to 56 primes below 1000, I now have a number with 64 primes
      > > > before n=1000. Is that some kind of record? (Weight=4.786)
      > > > (no 63s, 2 62s, 4 61s, 7 60s, 14 59s, 22 58s, 29 57s, not bad for 24 hours
      > > > work on a 5 year old machine.)
      > > >
      > > > Sure, it's  a 25-digit k, which detracts from the achievement (or
      > > > does it?), but even with numbers of that size I believe that >60
      > > > primes, in particular 64, before n=1000 must still be somewhat of
      > > > a rarity.
      > > >
      > > > I just don't have the 'feel' of how to measure these things yet.
      > >
      > > For the record, the best performing Riesel I have found at n=1000 is
      > > k=19122572047641*3*5*11*13*19*29*37*53 with 73 primes, the 73rd is at n=963
      >
      > Stunning!
      >
      > I don't know how up-to-date my database is, as I didn't fully get the website up and running whilst I was still priming, but the best I have to hand are the following:
      >
      > mysql> select * from records left join candidate on records.cand=candidate.id where n<=1000 && p>=70;
      > +------+----+-----+------+--------+--------------+---------------+------+------+
      > | cand | p | n | id | finder | k | m | plus | dual |
      > +------+----+-----+------+--------+--------------+---------------+------+------+
      > | 16 | 70 | 847 | 16 | g106 | 792030929331 | 2317696095 | 1 | 0 |
      > | 205 | 70 | 956 | 205 | pcrc | 55120464273 | 8341388245905 | -1 | 0 |
      > +------+----+-----+------+--------+--------------+---------------+------+------+
      >
      > Which is odd, as the m for the +1 case is the same small prime multiplier as yours, so my database has its signs all wrong (fortunately an easy fix).
      >
      > I did think that I broke clear of 70, but at the moment I have no proof of that. (And if I did, it was probably only 1 or 2 more.) I don't even know where all my files for that search even went. They were large enough, I may have just binned them :-(
      >
      > Good work, Robert!
      >
      > Phil
      >

      Phil

      A further advance, on the Riesel side, just failing at 75 primes:

      74 972 147707435198851 R 52
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