Re: How to generate wolframscript "PowersRepresentations[...]" output in PARI/GP

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Tue, Oct 03, 2023 at 09:31:12AM +0200, hermann@stamm-wilbrandt.de wrote:
> On 2023-10-02 20:54, Bill Allombert wrote:
> > 
> > If you want only one solution, you can do
> > 
> > foursquare(n) = abs(qfsolve(matdiagonal([1,1,1,1,-n]))[1..4]);
> > 
> > ? foursquare(17*29)
> > %15 = [0,0,13,18]~
> > 
> > ? foursquare(2^127-1)
> > %13 =
> > [3485713606461563310,6176908041673972933,4510469025815889567,9974590734764851407]~
> > 
> Thank you, that is fast and cool.
> 
> I tried qfsolve() on bigger numbers, and asked myself whether pari lib
> and C could speed up computation.
> 
> I looked at the 37 hits for "solve" in manual:
> https://pari.math.u-bordeaux.fr/pub/pari/manuals/2.15.4/libpari.pdf
> 
> I found qfbsolve() and cornacchia(), but nothing I could match to GP
> qfsolve().
> Is qfsolve() only available for GP?

Of course not:

? ??qfsolve
qfsolve(G):
...
   The library syntax is GEN qfsolve(GEN G).

Cheers,
Bill.