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PEN Problems
PEN O Problems
41
41
Part of
PEN O Problems
Problems
(1)
O 41
Source:
5/25/2007
Prove that for every positive integer
n
n
n
there exists an
n
n
n
-digit number divisible by
5
n
5^n
5
n
all of whose digits are odd.
induction
modular arithmetic