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Re: Why won't this sum evaluate?

On Jul 27, 5:20 am, PAR123 <reiser.p... at> wrote:
> In[120]:= $Version
> Out[120]= "7.0 for Mac OS X x86 (32-bit) (January 30, 2009)"
> In[122]:= Sum[c^n/(1 + c^(2*n)), {n, 1, Infinity}]
> Out[122]= -(1/4) + 1/4 EllipticTheta[3, 0, c]^2
> In[123]:= Sum[c^n/(1 + c^(2*n)), {n, 0, Infinity}]
> Out[123]= (won't simplify)
> The only thing different in the two sums is that the second sum is from 0 to Infinity rather than 1 to Infinity. Clearly, the n=zero term is 1/2.
> I have tried various Regularizations and Methods, (not exhaustively) but none seem to work on either of the sums, much less the last.
> A side problem - Is there a way to determine what Regularization and Method were used when none were specified?
> Thanks

I'm using the latest Mac version 8 and I get the same results as you

Gary Wardall

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