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

Re: primes such that every bit matters?

Expand Messages
  • djbroadhurst
    ... and is dwarfed by http://www.primenumbers.net/prptop/detailprp.php?rank=1 ... David
    Message 1 of 14 , Apr 4, 2013
      --- In primenumbers@yahoogroups.com,
      "WarrenS" <warren.wds@...> wrote:

      > this frightening number is a probable prime:
      > 19249+2^551542

      and is dwarfed by
      http://www.primenumbers.net/prptop/detailprp.php?rank=1
      > 2^9092392+40291

      David
    • Maximilian Hasler
      ... If you paste this into OEIS (and probably google, too) you will immediately find A137985 which in the first comment links to A065092, which in turn
      Message 2 of 14 , Apr 5, 2013
        >
        > A prime P which turns into a composite if you alter any bit in
        > its binary representation is an "every bit matters" prime.
        >
        > The examples below 10000 are
        > 127, 173, 191, 223, 233, 239, 251, 257, 277, 337, 349, 373, 431, 443,
        > ...

        If you paste this into OEIS (and probably google, too)
        you will immediately find A137985 which in the first comment links
        to A065092, which in turn refers to Paulsen's Prime Numbers Maze.

        Regards,
        Maximilian
      • Phil Carmody
        ... There is something weird though - and that s that huge quantities of stuff I looked at a decade ago is being rediscovered by Warren. This makes my
        Message 3 of 14 , Apr 9, 2013
          --- On Thu, 4/4/13, djbroadhurst wrote:
          > "WarrenS" <warren.wds@...> wrote:
          > > It's just a bit weird that I thought I had a totally original
          > > problem, and it turns out it has been worked on a ton by others
          > > for years...
          >
          > Why might that seem "weird" to you, Warren?
          > None of us should presuppose a monopoly on originality.

          There is something weird though - and that's that huge quantities of
          stuff I looked at a decade ago is being rediscovered by Warren. This
          makes my retirement from the field very hard, as he keeps posting
          things that I've been directly interested in. However, I'm happy, as
          a fresh mind approaching a problem can only ever increase the amount
          that is known, never diminish it. In particular, whilst my arithmetic
          may have been efficient, I was rarely good at the hard maths, so
          hopefully Warren can get past the road-blocks that I had way back when.

          Phil
          --
          () ASCII ribbon campaign () Hopeless ribbon campaign
          /\ against HTML mail /\ against gratuitous bloodshed

          [stolen with permission from Daniel B. Cristofani]
        Your message has been successfully submitted and would be delivered to recipients shortly.