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PEN Problems
PEN D Problems
16
16
Part of
PEN D Problems
Problems
(1)
D 16
Source:
5/25/2007
Determine all positive integers
n
≥
2
n \ge 2
n
≥
2
that satisfy the following condition; For all integers
a
,
b
a, b
a
,
b
relatively prime to
n
n
n
,
a
≡
b
(
m
o
d
n
)
⟺
a
b
≡
1
(
m
o
d
n
)
.
a \equiv b \; \pmod{n}\Longleftrightarrow ab \equiv 1 \; \pmod{n}.
a
≡
b
(
mod
n
)
⟺
ab
≡
1
(
mod
n
)
.
modular arithmetic
number theory
relatively prime
Congruences