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Old Jun27-09, 02:50 PM       Last edited by rman144; Jun27-09 at 03:01 PM..            #1
rman144

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Posts: 32
Zeta function and summation convergence

I need to know if the following series converges:

∑(k=1 to k=oo)[(((-1)^k) ζ(k))/(e^k)]


The problem is that zeta(1)=oo; however, the equation satisfies the conditions of convergence for an alternating series [the limit as k->oo=0 and each term is smaller than the last.]

Any thoughts?
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Old Jun27-09, 03:52 PM                  #2
*-<|:-D=<-<

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Posts: 95
Re: Zeta function and summation convergence

How did you arrive at the sum?
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Old Jun27-09, 05:53 PM                  #3
camilus

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Posts: 93
Re: Zeta function and summation convergence

well yeah I see what you're saying about zeta of 1. To see if the summation converges, try one of the tests, like tha ratio test.
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Old Jun28-09, 08:01 AM                  #4
g_edgar

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Posts: 388
Re: Zeta function and summation convergence

Originally Posted by rman144 View Post
I need to know if the following series converges:

∑(k=1 to k=oo)[(((-1)^k) ζ(k))/(e^k)]


The problem is that zeta(1)=oo; however, the equation satisfies the conditions of convergence for an alternating series [the limit as k->oo=0 and each term is smaller than the last.]

Any thoughts?
This one converges
LaTeX Code: <BR>\\sum_{k=2}^\\infty \\frac{(-1)^k \\zeta(k)}{e^k}<BR>

But in the original zeries, the LaTeX Code: k=1 term is the problem.
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Old Jun28-09, 04:18 PM                  #5
*-<|:-D=<-<

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Re: Zeta function and summation convergence

Yes if memory serves me right that sum is just a constant and an x away from being a taylor series of the digamma function.
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