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2023 Japan MO Finals
4
Nice NT problem
Nice NT problem
Source: 2023 Japan MO Finals 4
February 11, 2023
number theory
Problem Statement
Determine all positive integers
n
n
n
such that
n
n
n
divides
ϕ
(
n
)
d
(
n
)
+
1
\phi(n)^{d(n)}+1
ϕ
(
n
)
d
(
n
)
+
1
but
d
(
n
)
5
d(n)^5
d
(
n
)
5
does not divide
n
ϕ
(
n
)
−
1
n^{\phi(n)}-1
n
ϕ
(
n
)
−
1
.
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