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