generate random number through multiple iterations

I need to generate a random number over several iterations. Let me try and explain.

1. Iteration generates a random number from range(1, 100)) (no problem)

IF I choose two iterations then:

2. iteration generates a random number, where the value is limited to be +/- 20 of the result of 1. iteration. -still within 1-100.

And IF I choose three iteration then:

3. iteration generates a random number, where the value is limited to be +/- 20 of the result of 2. iteration. -still within 1-100.

and so on.