In order to determine the number of Vuza constructible canons of length
with
, we first realize that Vuza’s algorithm yields
different sets
and
different possibilities for
, which also consists of
elements. So, when exchanging the role of
and
, we have to take care to count only non-isomorphic canons. As a matter of fact, here in this case the process of exchanging
and
yields new canons, so that in addition to the previous
canons
we have another
canons of the form
. Hence, we end up with
Vuza constructible canons of length
with
. Moreover, there exist
Vuza constructible canons with
and
Vuza constructible canons with
, so that in conclusion there are
Vuza constructible canons of length
.
Finally, we want to deal with the question whether there exist regular complementary canons of maximal category which are not Vuza constructible canons. In Fripertinger (2002) for an integer
we introduced the function
defined on
such that
is the vector
consisting of
entries of
, and
is a vector consisting of
entries of
and
in the last position. We write the values of
in the form
If we apply
to each component of a vector
we get a vector
by concatenating all the vectors
. Among other properties we showed that
is the canonical representative of
if and only if
is the canonical representative of
.
is acyclic if and only if
is acyclic.
The mapping
can be considered as an augmentation, mapping a rhythm in
to an augmented rhythm in
. In correspondence with
, we define the mapping
which can be interpreted as
-fold subdivision. It also maps a rhythm in
to a rhythm in
. It is defined on
by
Again the value
for
is obtained by concatenation of the vectors
. It is easy to prove that the mapping
satisfies