Re: Game: find the integers

[American Citizen <website.reader3@gmail.com>]

This strongly suggests running the following GP-Pari script

for(i=0,100,for(j=1,10000000,n=j*(2^(2*i))-1;k=2*eulerphi(n)-n-1;if(k==0,print(2*i,",",j,",",n))))

but I am not sure of how much time this is going to take.

- Randall

On 11/6/24 13:48, Remigiusz Leon Suwalski wrote:
> 1, 3, 15, 255, 65535, 83623935, 4294967295, 6992962672132095 have this property (and no other number below 10^25) as stated in https://oeis.org/A050474.
>
> Cheers,
> Remigiusz
>
> On Thursday, November 7th, 2024 at 05:04, hermann@stamm-wilbrandt.de <hermann@stamm-wilbrandt.de> wrote:
>
> > On 2024-11-06 20:55, American Citizen wrote:
> >
> > > Bill
> > >
> > > Is this only true for values of n = 2^[1,2,4,8,16,32,64,128,256,512,
> > > etc] - 1 ??
> > >
> > > Randall
> > No:
> >
> > ? n=2^64-1;
> > ? 2*eulerphi(n)==n+1
> > 0
> > ?
> >
> >
> > Hermann.