Results 1 to 9 of 9

Math Help - Sequence 2,7,8,1,7,4,2,8,4,8,2,1,5,4,7,5,7,7,5,8,

  1. #1
    Newbie
    Joined
    Jan 2011
    Posts
    1

    Question Sequence 2,7,8,1,7,4,2,8,4,8,2,1,5,4,7,5,7,7,5,8,

    Ive been working this sequence for over a year now . Please help anyone

    2,7,8,1,7,4,2,8,4,8,2,1,5,4,7,5,7,7,5,8,

    there are two more numbers to the sequence but I just have not been able to get them Please help

    John
    Last edited by mr fantastic; January 27th 2011 at 11:58 PM. Reason: Re-titled.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor FernandoRevilla's Avatar
    Joined
    Nov 2010
    From
    Madrid, Spain
    Posts
    2,162
    Thanks
    45
    Quote Originally Posted by misterobsessed View Post
    Ive been working this sequence for over a year now . Please help anyone

    2,7,8,1,7,4,2,8,4,8,2,1,5,4,7,5,7,7,5,8,

    there are two more numbers to the sequence but I just have not been able to get them Please help

    There are twenty numbers: a_1,\ldots,a_{20} in your sequence. If I have understood correctly your question, you want to find a_{21} and a_{22} finding a determined rule. Well, in that case the correct answer is a_{21}=\alpha and a_{22}=\beta being \alpha and \beta chosen at random. And all of his as a consequence of a well known result about the Lagrange interpolation polynomial.


    Fernando Revilla
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Opalg's Avatar
    Joined
    Aug 2007
    From
    Leeds, UK
    Posts
    4,041
    Thanks
    7
    Quote Originally Posted by misterobsessed View Post
    Ive been working this sequence for over a year now . Please help anyone

    2,7,8,1,7,4,2,8,4,8,2,1,5,4,7,5,7,7,5,8,

    there are two more numbers to the sequence but I just have not been able to get them Please help

    John
    I can see why you think that a math help forum might be the place for this problem, but I suspect that the answer may not involve mathematics at all. If I had to guess, I would suspect that these numbers might perhaps be the lengths of the words in some saying, poem, song, something like that?

    Where did this sequence come from, and how do you know that there are only two more elements in it? If you can give us something of the background to the problem, it might give some clues about what the sequence represents.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Dec 2007
    From
    Ottawa, Canada
    Posts
    3,090
    Thanks
    67
    The sequence sure looks like the digits of e plus a few from pi thrown in!!

    Could even be forming 3 words, like from telephone: 2 = a,b,c 3 = d,e,f ... (1 = blank: separating words)
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Sep 2009
    Posts
    177
    Thanks
    1
    Quote Originally Posted by misterobsessed View Post
    Ive been working this sequence for over a year now . Please help anyone

    2,7,8,1,7,4,2,8,4,8,2,1,5,4,7,5,7,7,5,8,

    there are two more numbers to the sequence but I just have not been able to get them Please help

    John
    Sorry, but why would you work on this for over a year?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Newbie
    Joined
    Mar 2011
    Posts
    7
    It seems to me that this is a brute force random permutation...is this a snippet of code from a video game or audio program on shuffle?
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Apr 2011
    From
    Springfield, MO
    Posts
    2
    Well, it's very obviously not a function, so the previous posts noting that this isn't exactly a mathematical problem are very correct. I would tend to agree that it is probably a numerical transcription of some text.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,845
    Thanks
    320
    Awards
    1
    I wouldn't worry about it as the OP never made a response. Obviously it wasn't that important to him/her.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    When I see such a sequence the first thing I do if the general form is not obvious is search the Online Encyclopedia of Integer Sequences, and lo - it knows this sequence not.

    (this is probably a neopets puzzle)

    CB
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: August 24th 2010, 02:10 AM
  2. Replies: 0
    Last Post: July 4th 2010, 12:05 PM
  3. Replies: 2
    Last Post: March 1st 2010, 11:57 AM
  4. sequence membership and sequence builder operators
    Posted in the Discrete Math Forum
    Replies: 0
    Last Post: June 4th 2009, 03:16 AM
  5. Replies: 12
    Last Post: November 15th 2006, 12:51 PM

Search Tags


/mathhelpforum @mathhelpforum