Re: all divisors of a cyclotomic integer

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

On Sat, Jul 02, 2022 at 11:11:26PM +0200, Bill Allombert wrote:
> On Sat, Jul 02, 2022 at 03:16:27PM -0400, Max Alekseyev wrote:
> > Hello,
> > 
> > What would be the easiest way to get all divisors of a cyclotomic integer?
> > For example, how to get all divisors of 4 modulo polcyclo(21).
> 
> Use idealfactor and bnfisprincipal ?
> 
> bnf=bnfinit(polcyclo(21,a),1);
> id=idealfactor(bnf,4);
> {
>   my(L=List());
>   forvec(v=apply(a->[1,a],id[,2]),

Sorry, it should be
  forvec(v=apply(a->[0,a],id[,2]),
but hopefully you get the idea.

Cheers,
Bill.