How do i do the following i want to do a fill where it fills every 5th cell

example

A1 =1
A2 = 2
A3= 3
A4=4
A5 = 5
etc

I want to then do B1 = A1, B2 = A5, B3 = A10, etc. How do i do this with out
doing it manually?

Thanks,