The point isn’t hardcoding those numbers. The point is that you don’t iterate on any multiples of those numbers (which we know are composite) and doing allows u

The point isn’t hardcoding those numbers. The point is that you don’t iterate on any multiples of those numbers (which we know are composite) and doing allows us to eliminate 2/3 of the iterations. It’s an extension of enumerating over only odd numbers, which eliminates 1/2 of the iterations. Hardcoding those values is a semi-requirement of the above technique.