What is the 20th term...

What is the 20th term of the sequence: -5, -15, -45, -135,...?
Thanks for your help!

The sequence is geometric with common ration of r=3

a_n = (a_1)r^(n-1)

Or in this case

a_20 = (-5)3^19

a_20 = -5811307335

:)

- 5, - 15. - 45, - 135, - 405, - 1215, - 3645, - 10,935, - 32,805, - 98,415, - 295,245, - 885,735, - 2,657,205, - 7,971,615, - 23,914,845, - 71,744,535, - 215,233,605, - 645.700,815, -1937,102,445, - 5,811,307,335

your 20th term is - 5,811,307,335