What is the sum of the geometric series in which a1 = 2, r = 3, and an = 486? Hint: cap s sub n equals start fraction a sub one left parenthesis one minus r to the power of n end power right parenthesis over one minus r end fraction comma r ≠ 1, where a1 is the first term and r is the common ratio.

Sn = −1,254
Sn = −728
Sn = 81
Sn = 728