How do you insert a value in a function that is the previous y-value on the function table?

Question

I have to write a function for a table that is not linear. I know that to find the next value of y, you have to multiply the previous value of y by 3, but I don't know how to write a previous y in a function. The table is below.

 

x = 2,      3,      4,       5,       6

y = 6,    18,     54,   163,    486

Answer 1

Converting the table

 

x = 2,      3,      4,       5,       6

y = 2(3)  2(3²), 2(3³), 2(3⁴), 2(3⁵) 

 

y = 2(3)^x-1