Analysis of algorithm

1. Given this sequence of numbers:

         9        13        19        27        37

 a) What is the next number?

 b) Write in your own word an algorithm to solve this problem for any numbers.

2. Let's say we have the following sequence: 

n=1   S=9

n=2   S=13

n=3   S =19

n=4   S = 27

n=5   S = 37

 What is the value of S for n = 0  and n = 10? Explain how you get your answers.