2= 25

3=125

4=625

then 5= what?

1 is 5^1 = 5

2 is 5^2 = 25

3 is 5^3 = 125

4 is 5^4 = 625

See the pattern?, For the nth row is 5^n.

Hence, for what you wanted,

5 is 5^5 = 3125