Answer:
Unless im being completely braindead right now there isn't a whole number that works with this. When simplified its 5/2 or 2.5 but because it isn't an actual whole number (like 2, 4 and 6) they don't count.
(0,-1)(1,0)(2,3)(3,8)(4,15)
8 x 6 = 42 add two zeros so 4200
12.5 is the halfway point