A sequenceof non-negative integers satisfies
for some period-n juggling pattern f if and only if
is a permutation of
.
Suppose that f is a juggling pattern and. Then
so there is an integer-valued function
such
and
![]()
and
![]()
and the stated condition is satisfied.
Conversely, suppose that
![]()
is such that
is a permutation of
. If we define
for all integers t by extending the sequence periodically and then define
then f is the desired juggling pattern. To see that f is injective note that if
then
since
is injective modulo n. Then
. From
it follows that t = u and f is injective as claimed. To show that f is surjective, suppose that
. Since
is a permutation of
we can find a a t such that
. By adding a suitable multiple of n we can find a
such that
. This finishes the proof of the fact that any sequence satisfying the stated condition comes from a juggling pattern.