Real World Problem... Using log to find points in a graph?

I've been out of high school for 13 years so this may be an example to anyone viewing this that you do use these problems in the real world.

I've spent all day trying to figure this out and came home and found out I don't have any of my books from school (thanks wife).

I'm trying to write an equation to find points on a graph. It starts at (0,0), goes to (13,720) then to (78, 2160)

I found a few equations online but I just can't figure it out. I'd like to plug in at any point x to get y using those constants, but I've been at a loss all day.

Thanks for any help in advance. This is for a marketing internet project.