How do you write the explicit formula that represents the geometric sequence -2, 8, -32, 128?

Question

4300 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-02-12T22:56:58

Multiplying the previous term by -4 each time to get the next term, so:
#S_n = -2*(-4)^(n-1)#
Where n is the number of terms