A geometric sequence is defined recursively by a_n = 5 * a_(n-1). The 1st term of the sequence is 0.45. Which of the following is the explicit formula for the nth term of the sequence?
1) a_n = 5 * 0.45 * (n - 1)
2) a_n = 0.45 * 5 * (n + 1)
3) a_n = 0.45 * 5 * (n - 1)
4) a_n = 5 * 0.45 * n
5) a_n = 0.45 * 5 * n