Example 7.3
A simple numerical example of what we have just said is provided by n=10 Here, classes Sd are
These contain , respectively Therefore,
It is instructive to give a second proof of Theorem 7.6, This one depending on the fact that is multiplicative. The details are as follows. If n = 1,Then clearly
Assuming that n > 1 ,let us consider the number theoretic function
These contain integers,respectively therefore.
It is instructive to give a second proof of Theorem 7.6, This one depending on the fact that is multiplicative.
The details are as follows. If n=1,then clearly
Assuming that n>1, let us consider the number theoretic function
Because is known to be a multiplicative function, Theorem 6.4 asserts that F is also multiplicative. Hence, if n=P1 P2 is the prime factorization of n, them
for each value of i,
because the terms in the foregoing expression cancel each other, save for the term Pti Knowing this, we end up with
and so
as desired
We should mention in passing that there is another interesting identify that in volve the phi-function