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Problems
Contests
National and Regional Contests
PEN Problems
PEN A Problems
54
54
Part of
PEN A Problems
Problems
(1)
A 54
Source:
5/25/2007
A natural number
n
n
n
is said to have the property
P
P
P
, if whenever
n
n
n
divides
a
n
−
1
a^{n}-1
a
n
−
1
for some integer
a
a
a
,
n
2
n^2
n
2
also necessarily divides
a
n
−
1
a^{n}-1
a
n
−
1
. [*] Show that every prime number
n
n
n
has the property
P
P
P
. [*] Show that there are infinitely many composite numbers
n
n
n
that possess the property
P
P
P
.
Divisibility Theory