Re: SumOfSquaresRepresentations
- To: mathgroup at smc.vnet.net
- Subject: [mg103485] Re: [mg103475] SumOfSquaresRepresentations
- From: Carl Woll <carlw at wolfram.com>
- Date: Thu, 24 Sep 2009 07:50:39 -0400 (EDT)
- References: <200909240351.XAA13419@smc.vnet.net>
janos wrote:
> To be on the safe side:
> ClearAll[d, n, x, a, SumOfSquaresRepresentations];
>
> Take this from the help:
> SumOfSquaresRepresentations[d_, n_] :=
> Module[{x,
> a}, (a = Array[x, d]) /. {ToRules[Reduce[a.a == n, a, Integers]]}]
>
> Let's apply it:
> SumOfSquaresRepresentations[3, 15]
> {x$110[1], x$110[2], x$110[3]}
>
> And this is the only case that you get this funny result
> writing any integer between 1 and 200 in the place of 15.
>
> Any idea?
>
> Thank you.
>
> J=E1nos
>
>
Things are going wrong because there are no such representations.
If you have version 6/7, then you can use the built in function
PowersRepresentations instead. For example:
In[36]:= PowersRepresentations[15, 3, 2]
Out[36]= {}
showing you that there are no such representations.
Carl
- References:
- SumOfSquaresRepresentations
- From: janos <janostothmeister@gmail.com>
- SumOfSquaresRepresentations