- Jan 3, 2003Phil:
> Lower bound - anyone care for a stab?

0.

We believe (but cannot prove)

that there are an infinite number of primes of

the form primorial+1. That would be enough

to make f(p)=phi(p^2-1)/(p^2-1)

as close to zero as one likes.

At present we know that

p=392113#+1 is prime,

giving (a la Mertens)

f(p) < 0.0436

Can anyone get lower than that?

David - << Previous post in topic Next post in topic >>