sequence (x+1)^x + x^x

[Pfoertner, Hugo]

-----Original Message-----

Cino Hilliard's message contained (in part):
> >      print1(3" ");
> >      forstep(x=2,n,2,
> >        y=(x+1)^x+x^x;
> >         if(isprime(y),print1(y" "))
> >
> > Maybe someone can further limit the search or find more terms?
>

To which Jim Nastos replied (in part):
>   Since primality testing is costly for large numbers,
[...]

R. Shepherd replied:

> To which I add/clarify that it's my experience that even Pari's
*probable*-
> primality testing is costly for sufficiently large numbers
[...]

I have now tested up to x=6000, for which (x+1)^x+x^x is ~ 3*10^22669
and found nothing. Too bad, but I think it's time to give up here :-(

Hugo