Question

Given the geometric sequence: 19, 17111, 1539121, ⋯

Find an explicit formula for an, where the first term is a1=19.
an=

Find a6=

Answer 1

The sequence is not geometric!

17111/19 = 900.5789
1539121/17111 = 89.9492

the ratio is not constant. Fix it, find the common ratio r, and then

a6 = 19*r^5