20 Nov
2015
20 Nov
'15
7:07 p.m.
The data at OEIS's A051709 suggests that the answer to 1. is Yes and to 2. is No. And sigma(n) is the sum of the positive divisors of n. On Fri, Nov 20, 2015 at 8:05 PM, David Wilson <davidwwilson@comcast.net> wrote:
Is
1. Is phi(n) + sigma(n) - 2n >= 0 for all n > 1?
2. Is phi(n) + sigma(n) - 2n = 5 for any n?
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