math question "n(n-1)/2" - Page 2
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Thread: math question "n(n-1)/2"

  1. #11
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    I could be wrong, but doesn't this formula ensure it can't be a prime number?
    Luck--TSM
    Atlanta, GA


  2. #12
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    I could be wrong, but doesn't this formula ensure it can't be a prime number?
    Luck--TSM
    Atlanta, GA


  3. #13
    Jaded Network Admin nebulus200's Avatar
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    Uggh, been a really long time since I thought about this, but I am wanting to say the n(n-1)/2 has to do with permutations (all possible combinations of possibilities):

    http://www.cut-the-knot.org/do_you_k...mutation.shtml

    Number theory is a very large part of cryptography and permutation is a way to describe all the possibilties.

    Suggest looking into permutations and combinatorics (but be ready for some rather dry reading and some heavy math thinking). I think encryption relies heavily on this stuff (set theory, number theory).

    /nebulus
    There is only one constant, one universal, it is the only real truth: causality. Action. Reaction. Cause and effect...There is no escape from it, we are forever slaves to it. Our only hope, our only peace is to understand it, to understand the 'why'. 'Why' is what separates us from them, you from me. 'Why' is the only real social power, without it you are powerless.

    (Merovingian - Matrix Reloaded)

  4. #14
    Jaded Network Admin nebulus200's Avatar
    Join Date
    Jun 2002
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    1,356
    Uggh, been a really long time since I thought about this, but I am wanting to say the n(n-1)/2 has to do with permutations (all possible combinations of possibilities):

    http://www.cut-the-knot.org/do_you_k...mutation.shtml

    Number theory is a very large part of cryptography and permutation is a way to describe all the possibilties.

    Suggest looking into permutations and combinatorics (but be ready for some rather dry reading and some heavy math thinking). I think encryption relies heavily on this stuff (set theory, number theory).

    /nebulus
    There is only one constant, one universal, it is the only real truth: causality. Action. Reaction. Cause and effect...There is no escape from it, we are forever slaves to it. Our only hope, our only peace is to understand it, to understand the 'why'. 'Why' is what separates us from them, you from me. 'Why' is the only real social power, without it you are powerless.

    (Merovingian - Matrix Reloaded)

  5. #15
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    Jun 2002
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    ( 3 * (3 - 1) ) / 2 = 3
    for n = 3, this function demonstrates a property Karma - you get what you give - and a prime to boot.
    Hmm...theres something a little peculiar here. Oh i see what it is! the sentence is talking about itself! do you see that? what do you mean? sentences can\'t talk! No, but they REFER to things, and this one refers directly-unambigeously-unmistakably-to the very sentence which it is!

  6. #16
    Senior Member
    Join Date
    Jun 2002
    Posts
    394
    ( 3 * (3 - 1) ) / 2 = 3
    for n = 3, this function demonstrates a property Karma - you get what you give - and a prime to boot.
    Hmm...theres something a little peculiar here. Oh i see what it is! the sentence is talking about itself! do you see that? what do you mean? sentences can\'t talk! No, but they REFER to things, and this one refers directly-unambigeously-unmistakably-to the very sentence which it is!

  7. #17

    sharing "why?"

    Now i know why...

    Actually it came from arithmetic series where we could assume that

    t1 = 0 = 0
    t2 = 1 = 0 + 1
    t3 = 3 = 0 + 1 + 2
    t4 = 6 = 0 + 1 + 2 + 3

    where a(initial number) a=0
    and the d(differences) d = 1

    we put it in arithmetic series formula Sn = (n/2)(2a+(n-1)d)

    = (n/2)(2(0)+(n-1)(1))

    =(n/2)(n-1)

    tn = (n/2)(n-1) thanks!

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