If the sum of the first n terms of a sequence an is Sn = a ^ n-1 (a ≠ 0), then what is the characteristic of the sequence? What is the sequence? And prove it It's the nth power of a minus 1 Is it possible to be an arithmetic sequence?

If the sum of the first n terms of a sequence an is Sn = a ^ n-1 (a ≠ 0), then what is the characteristic of the sequence? What is the sequence? And prove it It's the nth power of a minus 1 Is it possible to be an arithmetic sequence?

an=sn-s(n-1)
=a^n-a^(n-1)
=(a-1)a^(n-1)
So it's an equal ratio sequence, the first term is (A-1), and the common ratio is a
impossible
Because an-a (n-1) is not constant