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PEN J Problems
17
J 17
J 17
Source:
May 25, 2007
function
number theory
totient function
Divisor Functions
Problem Statement
Show that
ϕ
(
n
)
+
σ
(
n
)
≥
2
n
\phi(n)+\sigma(n) \ge 2n
ϕ
(
n
)
+
σ
(
n
)
≥
2
n
for all positive integers
n
n
n
.
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