Re: number of ways of writing a nonnegative integer n as a sum of 3 squa

Thomas D. Dean on Tue, 05 Dec 2023 19:53:13 +0100

Re: number of ways of writing a nonnegative integer n as a sum of 3 squares (zero being allowed).

To: pari-users@pari.math.u-bordeaux.fr
Subject: Re: number of ways of writing a nonnegative integer n as a sum of 3 squares (zero being allowed).
From: "Thomas D. Dean" <tomdean@wavecable.com>
Date: Mon, 4 Dec 2023 01:46:08 -0800
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On 12/4/23 01:17, Bill Allombert wrote:
...

Try this:
fun(n)=my(a=sqrtint(n),c=0);for(i=-a,a,for(j=-a,a,for(k=-a,a,if(i^2+j^2+k^2==n,print(c++,":",[i,j,k])))));


...

I distributed nonnegative thru n and i,j,and k.

Sorry for the noise. But, all was not wasted, I learned something.

Tom Dean

References:
- number of ways of writing a nonnegative integer n as a sum of 3 squares (zero being allowed).
  - From: "Thomas D. Dean" <tomdean@wavecable.com>
- Re: number of ways of writing a nonnegative integer n as a sum of 3 squares (zero being allowed).
  - From: Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>