(New page: Spencer, I am skeptical about your formula. you posted: <math>\sum_{i=1}^n\frac{n}{n - i + 1}\!</math> being equal to <math>\sum_{i=1}^n a_i = \frac{n(a_1+a_n)}{2}\!</math> Try n=...)
 
 
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My calculation my be wrong, but otherwise I am thinking I might leave the formula as the answer.
 
My calculation my be wrong, but otherwise I am thinking I might leave the formula as the answer.
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I agree with Ben. <math>\sum_{i=1}^n\frac{n}{n - i + 1} = \frac{n}{n} + \frac{n}{n-1} + \dots + \frac{n}{3} + \frac{n}{2} + \frac{n}{1}</math> is '''not''' an arithmetic series!
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-Brian

Latest revision as of 18:29, 6 October 2008

Spencer, I am skeptical about your formula.

you posted:

$ \sum_{i=1}^n\frac{n}{n - i + 1}\! $

being equal to

$ \sum_{i=1}^n a_i = \frac{n(a_1+a_n)}{2}\! $


Try n=3

original expected value would be 11/2 = 5 1/2

your formula yields 6.

My calculation my be wrong, but otherwise I am thinking I might leave the formula as the answer.


I agree with Ben. $ \sum_{i=1}^n\frac{n}{n - i + 1} = \frac{n}{n} + \frac{n}{n-1} + \dots + \frac{n}{3} + \frac{n}{2} + \frac{n}{1} $ is not an arithmetic series!

-Brian

Alumni Liaison

Correspondence Chess Grandmaster and Purdue Alumni

Prof. Dan Fleetwood