While working on their homework on sequences, Davis was suddenly stumped! 

“This problem doesn’t make sense!” he exclaimed.  Tess was working on her homework as well. 

"What's the problem?” she asked.

"This problem is about a SEQUENCE, $t\left(n\right) = 9n − 2$ , but it is asking whether or not it is a function. How can a sequence be a function?”

“Well of course a sequence is a function!” said Tess.

Who is right?  Should Davis be confused, or is Tess correct?  What is the difference between a sequence and a function?  Explain completely.