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Chile Contests
Chile National Olympiad
1994 Chile National Olympiad
3
3
Part of
1994 Chile National Olympiad
Problems
(1)
prime with n digits all equal to 1 (Chile NMO 1994 P3)
Source:
11/21/2021
Let
x
x
x
be an integer of
n
n
n
digits, all equal to
1
1
1
. Show that if
x
x
x
is prime, then
n
n
n
is also prime.
prime
number theory
Digits