From the January 2016 Common Core Algebra I Regents

According to www.regentsprep.org:
“Recursion is the process of choosing a starting term and repeatedly applying the same process to each term to arrive at the following term.  Recursion requires that you know the value of the term immediately before the term you are trying to find.”

This question is all about notation.  Recursive means what happens to each number so that it becomes the next number in the sequence. 

How can we get from 3 to 7 and then from 7 to 15?  and then from 15 to 31.  Each new number in pink is just a little bit more than double the previous number.  Look carefully at all four choices — only one of them is close to multiplying by 2.

f(1) = 3 means that the first number of the sequence is 3 which appears in all 4 answers.
f(n + 1) means the next number in the sequence.  

 Find the one that matches the given pattern 🙂