Is this relation a function?

What are the first 4 terms in the multiplication pattern given by the formula 2×4n

If u good at math hit me up on insta or sum @basic_jaiden or @ and

Plzz ! if you were constructing a triangular frame, and you had wood in the length of 4 inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood? yes or no? = explain your mathematical thinking/show your work: