Question 475308
Well look at the first four terms of the sequence:
{{{-1/7}}},{{{-6/7}}},{{{-36/7}}}...
Now notice you could factor out a common factor of {{{-1/7}}} from each term.
Then the sequence would look like the following for n=1,2,3
n =  1, 2, 3 ...
An = 1, 6, 36 ...
establish a relationship and see if the pattern holds
{{{1 = 6^0 = 6^(1-1) = 6^(n-1)}}}
{{{6 = 6^1 = 6^(2-1) = 6^(n-1)}}}
{{{36 = 6^2 = 6^(3-1) = 6^(n-1)}}}
It does.
Therefore An = {{{(-1/7)*6^(n-1)}}}