[seqfan] Re: Finding numbers represented by indefinite binary quadratic forms

[Neil Sloane]

Max, Thanks for that link! I tried entering
1
3
-3
0
0
-15
but that seems to have killed the website. I agree that it doesn't always
work!

Best regards
Neil


On Wed, Jun 4, 2014 at 7:42 AM, Max Alekseyev <maxale at gmail.com> wrote:

> There is an online solver for this kind of equaitons by Dario Alpern:
> http://www.alpertron.com.ar/QUAD.HTM
> (which however does not always work correctly)
>
> Regards,
> Max
>
>
> On Wed, Jun 4, 2014 at 12:41 AM, Neil Sloane <njasloane at gmail.com> wrote:
> > Does anyone have a program for doing the following:
> >
> > Given an indefinite binary quadratic form ax^2+bxy+cy^2 (with
> discriminant
> > b^2-4ac>0 and not a square) and a positive or negative number n, decide
> if
> > ax^2+bxy+cy^2 = n has a solution.
> >
> > (If n = p is a prime, one can use the PARI command
> qfbsolve(Qfb(a,b,c),p) )
> >
> > Neil
> >
> > _______________________________________________
> >
> > Seqfan Mailing list - http://list.seqfan.eu/
>
> _______________________________________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>



-- 
Dear Friends, I have now retired from AT&T. New coordinates:

Neil J. A. Sloane, President, OEIS Foundation
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com