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Sun 21 Jan, 2007 11:24 am
What is the formula for teh sequence?!? Does anyone knoww?!?
... 0, 4, 10, 20, 35 ....
Anyone out theree?!? Can you please explain to my simple brainnnn?
x
Are you sure it isn't
1, 4, 10, 20, 35, ...?
Hmm...
Actually i think it is.. yeah it iss.. thankss.. so do you know the formula for it? x
I think he just made a lucky guess.
Look at the differences of successive terms. Familiar?
Not particually.. explain...
It's related to another question you posted.
nth term = SUM (from x=1 to n) of x(x+1)/2
Niiiiiice car markr!
Just your colour.
Further to the above, it looks like the nth term is a cubic function of n which can be established by solving simultaneous equations for the coefficients a b c d using
nth term= an^3 + bn^2 + cn + d
LATER EDIT
Hence nth term = (n^3 + 3n^2 + 2n)/6
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