Find all the powers of 4 in the range 4 through 1000

4 raised to power 1 = 4¹ = 4

4 raised to power 2 = 4² = 16

4 raised to power 3 = 4³ = 64

4 raised to power 4 = 4⁴ = 256

4 raised to power 2 = 4⁵ = 1024. This is outside the range, so it is excluded.

All the powers are 4, 16, 64 and 256