There are at least two statements which go by the name of Artin's conjecture.
If 
is any complex finite-dimensional representation of the absolute Galois
group of a number field, then Artin showed how
to associate an 
-series
with it. These 
-series directly generalize zeta functions and Dirichlet 
-series, and as a result of work by Richard
Brauer, 
is known to extend to a meromorphic function
on the complex plane. Artin's conjecture predicts
that it is in fact holomorphic, i.e., has
no poles, with the possible exception of a pole at 
(Artin 1923/1924). Compare with the generalized
Riemann hypothesis, which deals with the locations of the zeros of certain 
-series.
The second conjecture states that every integer not equal to 
or a square number is a primitive root modulo 
for infinitely many 
and proposes a density for the set of such 
which are always rational multiples of a constant known as
Artin's constant. There is an analogous theorem
for functions instead of numbers which has been proved by Billharz (Shanks 1993,
p. 147).
-Reihen." Abh. Math. Sem. Univ. Hamburg 3,
89-108, 1923/1924.Matthews, K. R. "A Generalization of Artin's
Conjecture for Primitive Roots." Acta Arith. 29, 113-146, 1976.Moree,
P. "A Note on Artin's Conjecture." Simon Stevin 67, 255-257,
1993.Ram Murty, M. "Artin's Conjecture for Primitive Roots."
Math. Intell. 10, 59-67, 1988.Shanks, D.