Mangoldt's function is defined as
![]()
A short list of values of
is given below
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1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
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0 |
|
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0 |
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|
0 |
The Mangoldt function arises naturally in the fundamental theorem of arithmetic. If we take natural logs of the prime power factorisation of
we obtain![]()
The only nonzero terms in the sum come from those divisors
of the form
for
and![]()
Hence![]()
is a very useful formula.
We can invert this expression to obtain
in terms of natural logs using the following theorem.
Theorem
If
then![]()
Proof:
where
The inverse to
is
the Mobius function so![]()
for all
so![]()