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Next number

  1. Sep 5, 2010 #1
    What is the next number in the following series?

    2, 3, 4, 9, 6, 12, 8, 15, 16, 18, 12, 28, 14, 24, 24, 25...

    (and can you prove that there would be an infinite number of contiguous pairs thereabouts?:eek:)
  2. jcsd
  3. Sep 6, 2010 #2
    I'm an undergrad in EE, so I'm not much on number theory. School is starting back up so I thought I'd take a try to get my brain back in the swing of things. I thought of it as a bunch of ramp signals... I know i'm not right, but is this even in the right direction?

    I got 4 signals

    [;y_1(n) = 2 + n;]
    [;y_2(n) = \frac{9}{2} + \frac{3*n}{2};]
    [;y_3(n) = -16+4*n;]
    [;y_4(n) = 10+n;]

    I don't like the last one. The first three seem to have some sort of pattern. But you can get an expression for the signal by simply doing

    [;y(n) = y_1(n)+y_1(n-1)+y_1(n-2)+y_2(n-3)+y_1(n-4)+y_2(n-5);], etc

    No answer though.

    See attachment for matlab stuffs

    Attached Files:

    Last edited: Sep 6, 2010
  4. Sep 6, 2010 #3
    UR -- thank you for your hard work, but I included only two simple functions toward each number of this series. I think you would do better by mentally seeking a pattern.

    Thanks for an introduction to ramp signals -- are these all linear?

    (Apparently there is a website where you can look up most known series.)

    Exceed in school!
    Last edited: Sep 6, 2010
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