### get multiplicative subgroup of Z/nZ

Is it possible to get a multiplicative group object of integers modulo n?

For example for n=15 the elements are {1,2,4,7,8,11,13,14}

Of course I can get the elements itself with

R = Integers(15)

R.list_of_elements_of_multiplicative_group()

but not as a group.

It is also possible to construct the isomorphic group ~~as AbelianGroup,
~~C2 x C4,
but then the elements are not ~~integers...~~integers:

AbelianGroup([2,4])