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2013 IMAC Arhimede
2
2
Part of
2013 IMAC Arhimede
Problems
(1)
4^{6^n}+1943 dividible by 2013
Source: IMAC Arhimede 2013 p2
5/6/2019
For all positive integer
n
n
n
, we consider the number
a
n
=
4
6
n
+
1943
a_n =4^{6^n}+1943
a
n
=
4
6
n
+
1943
Prove that
a
n
a_n
a
n
is dividible by
2013
2013
2013
for all
n
≥
1
n\ge 1
n
≥
1
, and find all values of
n
n
n
for which
a
n
−
207
a_n - 207
a
n
−
207
is the cube of a positive integer.
number theory
perfect cube
divisible
exponential