Answer:
43rd term
Step-by-step explanation:
Arithmetic sequences are basically linear functions, so the same value is added every time. So, knowing that Asub1 is equal to one, and Asubn is equal to 169 we can take 169-1 and divide by our common difference. This is four as 5-1=4 and 9-5=4.
So, (169-1)/4=42.
This is however 42 terms after Asub1, so this would be the 43rd teen of the sequence!