Let
be an odd prime,
be an integer such that
and
, and
Then the following are equivalent
1.
is prime.
2. There exists an integer with
such that
and
,
where GCD is the greatest common divisor (i.e.,
and
are relatively prime). The underlying argument
appears in Pocklington (1914/16, pp. 29-30) and Lehmer (1927, pp. 331-332).