[Tutor] Quick Programming Question

[Jared Johnson]

 I've been stuck on this for a while now and was wondering if you could help.
The question is: 
"A pentagonal number is defined as n(3n - 1)/2 for n = 1,2 etc. So, the first few numbers are 1, 5, 12, 22 etc. Write a function with the following header that returns a pentagonal number:
def getPentagonalNumber(n):
Write a test program that uses this function to display the first 100 pentagonal numbers with 10 numbers on each line."
I am very new at programming and if you could help me out at all by putting this is the simplest terms, that would be extremely helpful! 
Thanks!