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New Record Prime Found

Posted by ryuzaki0 on from the mersenne-is-a-gimp dept.

An anonymous reader writes, "The GIMPS project has found a new record prime. 2 ^ 32,582,657 - 1, clocking in at over 9 million digits, is a Mersenne prime, as were the last few record primes. Here is the 9-megabyte decimal expansion."

4 of 112 comments (clear)

  1. Re:Help by Beached · · Score: 0, Redundant

    2^4-1 = 15 = 3*5 Not prime

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    ---- aut viam inveniam aut faciam
  2. Re:Help by knewter · · Score: 0, Redundant

    I almost feel silly doing this...

    2^4=16
    16-1=15
    15=3x5

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    -knewter
  3. Re:Help by Halo- · · Score: 0, Redundant

    I thought that all numbers in the form 2^n -1 are prime - If I am correct, what's so new about this number? -Nicolas

    Nope, most of them aren't:
    (2^3)-1 = 8 - 1 = 7 (prime)
    (2^4)-1 = 16 - 1 = 15 (not prime, 3, 5)
    (2^5)-1 = 32 - 1 = 31 (prime)
    (2^6)-1 = 64 - 1 = 63 (prime)
    (2^7)-1 = 128 - 1 = 127 (prime)
    (2^8)-1 = 256 - 1 = 255 (not prime, 3, 5)
    etc..

  4. Re:Help by FhnuZoag · · Score: 0, Redundant

    Good lord, no.

    Take 2^4 - 1 = 15 = 3 * 5