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6
$n! + a$ divides $(2n)!$
$n! + a$ divides $(2n)!$
Source:
August 11, 2015
number theory
Problem Statement
Suppose that
a
a
a
is an integer and that
n
!
+
a
n! + a
n
!
+
a
divides
(
2
n
)
!
(2n)!
(
2
n
)!
for infinitely many positive integers
n
n
n
. Prove that
a
=
0
a = 0
a
=
0
.
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