Notice that each y value is the square of an integer.
4 = 2^2
9 = 3^2
16 = 4^2
etc.
This is a quadratic equation.
The first ordered pair is (0, 4). 4 is 2^2, so add 2 to x and rthen square the quantity. (0 + 2)^2 = 2^2 = 4. This also works for the other values of x.