The 12 out front of A(n) means we multiply 12 and A(n) to get the next term A(n+1). We do this as many times as we want to generate as many terms as we want.
We start with the first term 4
The second term is 4*12 = 48
The third term is 48*12 = 576
The fourth term is 576*12 = 6912
The first four terms are 4, 48, 576, and 6912.