Liouville's function denotedis defined as follows:
Liouville's function is completely multiplicative since ifand
then
Theorem
Forwe have
Also for all
Proof: Letthen
is multiplicative so to determine
we only need to compute
for all
We have
Hence ifwe have
If any exponent
is odd then
so
If all the exponents are even then
for all
and
This shows that
is a square and
otherwise. Also