Maybe declare(sum, linear) can help.
> -----Message d'origine-----
> De?: maxima-bounces at math.utexas.edu [mailto:maxima-bounces at math.utexas.edu] De la part de
> Robert Dodier
> Envoy??: vendredi 24 mai 2013 19:33
> ??: maxima at math.utexas.edu
> Objet?: Re: [Maxima] simplifying sums
>
> On 2013-05-24, Przemek Klosowski <przemek.klosowski at nist.gov> wrote:
>
>
> > My first newbie question is what is that construct 'sum(),simpsum'? is
> > simpsum a procedure evaluated on output of sum(), or some global flag?
>
> Well, simpsum is an evaluation flag -- at the input prompt, 'foo, flag'
> is equivalent to ev(foo, flag) -- see ev for a list of flags. What
> happens is that a different simplification function is called when the
> flag is present.
>
> > My real summation formula is sum(binomial(k+1,2)^(n-k),k,1,n)
>
> The built-in simplification for sums isn't very strong. There is an
> add-on package simplify_sum which is more powerful. However I find that
> even simplify_sum can't solve this one:
>
> (%i1) display2d : false $
> (%i2) load (simplify_sum) $
> (%i3) sum (binomial (k + 1, 2)^(n - k), k, 1, n);
> (%o3) 'sum(k^(n-k)*(k+1)^(n-k)*2^(k-n),k,1,n)
> (%i4) simplify_sum (%);
> (%o4) 'sum(k^(n-k)*(k+1)^(n-k)*2^(k-n),k,1,n)
>
> Sorry I can't be more helpful,
>
> Robert Dodier
>
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