SOLUTION: How would you write the recursive rules for the following sequences: 1. 3, 12, 48, 192, 768,...

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Question 295484: How would you write the recursive rules for the following sequences:
1. 3, 12, 48, 192, 768,...
Found 2 solutions by richwmiller, Edwin McCravy:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
a_n = 3*4^(n-1)
next term 3072

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!

The other tutor gave the formula for the nth term,
not the recursive rule.

You multiply by 4 each time, so

a%5Bn%2B1%5D-%22%22%22=%224%2Aa%5Bn%5D,  a%5B1%5D=3

or it can be written 

a%5Bn%5D%22=%224%2Aa%5Bn-1%5D-%22%22, a%5B1%5D=3

Edwin