Yes this is an exponential function. One way we can determine this is to notice how each y term is multiplied by 6 to get the next y term
example: -2 times 6 = -12
another example: -12 times 6 = -72
The exponential function that models this data is y = -2*6^(x-1). Note how plugging in x = 1 leads to y = -2. Plugging in x = 2 leads to y = -12, and so on.