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Problems
Contests
National and Regional Contests
PEN Problems
PEN A Problems
41
41
Part of
PEN A Problems
Problems
(1)
A 41
Source:
5/25/2007
Show that there are infinitely many composite numbers
n
n
n
such that
3
n
−
1
−
2
n
−
1
3^{n-1}-2^{n-1}
3
n
−
1
−
2
n
−
1
is divisible by
n
n
n
.
modular arithmetic
Divisibility Theory