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International Contests
Austrian-Polish
2003 Austrian-Polish Competition
7
7
Part of
2003 Austrian-Polish Competition
Problems
(1)
n!^{f(n)} divides (n^n)! when f(n) = (n^n - 1)/(n - 1)
Source: Austrian Polish 2003 APMC
4/25/2020
Put
f
(
n
)
=
n
n
−
1
n
−
1
f(n) = \frac{n^n - 1}{n - 1}
f
(
n
)
=
n
−
1
n
n
−
1
. Show that
n
!
f
(
n
)
n!^{f(n)}
n
!
f
(
n
)
divides
(
n
n
)
!
(n^n)!
(
n
n
)!
. Find as many positive integers as possible for which
n
!
f
(
n
)
+
1
n!^{f(n)+1}
n
!
f
(
n
)
+
1
does not divide
(
n
n
)
!
(n^n)!
(
n
n
)!
.
number theory
divides
factorial
divisible