Results 1 to 4 of 4

Math Help - Interesting sequence - find closed form

  1. #1
    Junior Member
    Joined
    Feb 2009
    Posts
    57

    Interesting sequence - find closed form

    This sequence has me stumped.... anyone have an idea on what the closed form is?

    0, 1, 4, 12, 28, 55, 96, 154
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by vexiked View Post
    This sequence has me stumped.... anyone have an idea on what the closed form is?

    0, 1, 4, 12, 28, 55, 96, 154
    I'm not surprised, see this

    CB
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Sep 2009
    Posts
    6
    Quote Originally Posted by CaptainBlack View Post
    I'm not surprised, see this

    CB
    Whoa! awesome resource. CaptainBlack, can you point me to a sticky with useful links such as that? I've been searching around with the google, but come up with too much random junk.

    Thanks!
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member
    Joined
    Jun 2009
    Posts
    220
    Thanks
    1
    Quote Originally Posted by vexiked View Post
    This sequence has me stumped.... anyone have an idea on what the closed form is?

    0, 1, 4, 12, 28, 55, 96, 154
    Labelling a_0, a_1, a_2, \ldots . Then a_1 is the first triangular number, a_2 is the second square number, a_3 is the third pentagonal number, etc...

    I'm just working on a closed form but it shouldn't be too difficult at all.

    Pomp

    EDIT: a_n = n \left( {}^nC_2 + 1 \right) works.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. closed form for sequence z=z^2+c & generating function
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: October 4th 2011, 03:05 AM
  2. Closed form for a sequence
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: February 14th 2010, 01:37 AM
  3. closed form sequence
    Posted in the Number Theory Forum
    Replies: 2
    Last Post: June 9th 2009, 03:06 PM
  4. Writing a sequence in closed form
    Posted in the Calculus Forum
    Replies: 4
    Last Post: April 18th 2009, 03:37 PM
  5. Geometric Sequence, find a closed form.
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 18th 2009, 06:51 AM

Search Tags


/mathhelpforum @mathhelpforum