ASKSAGE: Sage Q&A Forum - Individual question feedhttp://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Thu, 15 Nov 2012 01:55:38 -0600Unexpected result for the sum of a serieshttp://ask.sagemath.org/question/9537/unexpected-result-for-the-sum-of-a-series/I typed
n = var('n')
sum(1/((2*n-1)^2*(2*n+1)^2*(2*n+3)^2), n, 0, oo)
sage answered
3/256*pi^2 - 1/32
By hand computation (via Fourier series), and by WolframAlpha I got
3/256*pi^2
Why?
[Link to WolframAlpha's result](http://www.wolframalpha.com/input/?i=sum%281%2F%28%282*n-1%29%5E2*%282*n%2B1%29%5E2*%282*n%2B3%29%5E2%29%2C+n%2C+0%2C+oo%29).
(This is my first question. If it is inappropriate here, please tell me where I should ask it. I used the tag "bug", but I of course mean "potential bug". Thank you very much in advance!)
Wed, 14 Nov 2012 19:48:43 -0600http://ask.sagemath.org/question/9537/unexpected-result-for-the-sum-of-a-series/Answer by burcin for <p>I typed</p>
<pre><code>n = var('n')
sum(1/((2*n-1)^2*(2*n+1)^2*(2*n+3)^2), n, 0, oo)
</code></pre>
<p>sage answered</p>
<pre><code>3/256*pi^2 - 1/32
</code></pre>
<p>By hand computation (via Fourier series), and by WolframAlpha I got </p>
<p>3/256*pi^2</p>
<p>Why?</p>
<p><a href="http://www.wolframalpha.com/input/?i=sum%281%2F%28%282*n-1%29%5E2*%282*n%2B1%29%5E2*%282*n%2B3%29%5E2%29%2C+n%2C+0%2C+oo%29">Link to WolframAlpha's result</a>.</p>
<p>(This is my first question. If it is inappropriate here, please tell me where I should ask it. I used the tag "bug", but I of course mean "potential bug". Thank you very much in advance!)</p>
http://ask.sagemath.org/question/9537/unexpected-result-for-the-sum-of-a-series/?answer=14270#post-id-14270This is a bug. It is now [#13712](http://trac.sagemath.org/sage_trac/ticket/13712) on the Sage issue tracker.
Sage calls Maxima to evaluate symbolic sums. Somebody will have to pass the report upstream to the Maxima developers.
Thanks for your report.Wed, 14 Nov 2012 23:39:42 -0600http://ask.sagemath.org/question/9537/unexpected-result-for-the-sum-of-a-series/?answer=14270#post-id-14270Comment by kcrisman for <p>This is a bug. It is now <a href="http://trac.sagemath.org/sage_trac/ticket/13712">#13712</a> on the Sage issue tracker.</p>
<p>Sage calls Maxima to evaluate symbolic sums. Somebody will have to pass the report upstream to the Maxima developers.</p>
<p>Thanks for your report.</p>
http://ask.sagemath.org/question/9537/unexpected-result-for-the-sum-of-a-series/?comment=18703#post-id-18703This has been reported upstream at [Maxima artifact 3587514](https://sourceforge.net/tracker/?func=detail&aid=3587514&group_id=4933&atid=104933).Thu, 15 Nov 2012 01:55:38 -0600http://ask.sagemath.org/question/9537/unexpected-result-for-the-sum-of-a-series/?comment=18703#post-id-18703