Use the integral test.
I guess you need some heavy machinery for this. The n'th prime number satisfies , because of the prime number theorem. Also (obviously) and so
Therefore . But converges, by the integral test. Hence, by the comparison test, so does
In...
http://www.mathhelpforum.com/math-he...ers-84832.html
... it has been demonstrated that...
(1)
... where...
(2)
Now is...
(3)
... so that...
(4)
Kind regards