Arecursive rule for a geometric sequence is a1=49; an=3an−1 . what is the explicit rule for this sequence?

The explicit rule for the geometric sequence is in the form,

              an = (a1)^(r -1)

where an is the nth term, a1 is the first term, and r is the common ratio. Substituting the known terms from the given above, we arrive to the explicit form of the sequence which is,

            an = 49^(3 - 1)