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

Re: Prime/Pseudo Prime question

Expand Messages
  • Kevin Acres
    Hi David, I can only give you the numbers that I get here: 2 is even and won t be accepted. 3 divides 2^2 -1 191 divides 2^95 - 1 307 divides 2^102 - 1 593
    Message 1 of 4 , Jun 30, 2004
    • 0 Attachment
      Hi David,

      I can only give you the numbers that I get here:

      2 is even and won't be accepted.

      3 divides 2^2 -1
      191 divides 2^95 - 1
      307 divides 2^102 - 1
      593 divides 2^148 - 1
      839 divides 2^419 - 1
      3593 divides 2^1796-1
      3989 divides 2^3988-1
      4051 divides 2^50-1
      6691 divides 2^6690-1
      152429 divides 2^152428 - 1
      2349679 divides 2^391613 - 1
      17504141 divides 2^17504140 - 1

      As I said, trivial and totally deterministic :-)

      Regards,

      Kevin.




      At 10:04 PM 30/06/2004, you wrote:
      >A test case:
      >
      >? x=426315489966437174530195419710289226952407399;
      >? print(factor(x-1)[,1]~)
      >[2, 3, 191, 307, 593, 839, 3593, 3989, 4051, 6691, 152429, 2349679, 17504141]
      >
      >For which p does x divide 2^p-1 ?
      >
      >Everyone can go through the list checking each case, with modular
      >arithmetic and binary exponentiation.
      >
      >But can you tell in advance what the answer is, without doing
      >all those powermods?
      >
      >David
    Your message has been successfully submitted and would be delivered to recipients shortly.