Presumably, you are assuming that each time you (figuratively) "press =", it will raise the number in the display to the 10th power, just as when you press = (in some calculators) after entering "1 + 1", it will add 1 again:
1 + 1 = 2
= 3 [i.e. 2 + 1 = 3]
= 4 [i.e. 3 + 1 = 4]
...
and the result after doing this n times (I did it 3 times) will be f(n) = n+1. That's the sort of answer you are asking for, a simple formula for the result of applying the same operation n times.
That is, the process can be expressed in terms of functions as
f(1) = 1 + 1 = 2
f(2) = f(1) + 1 = 3
f(3) = f(2) + 1 = 4
Have I got that right?
So you want this:
10^10 = 1*10^10 [scientific notation]
= 1*10^100 [i.e. (10^10)^10 = 1*10^100]
= 1*10^1000 [i.e. ((10^10)^10)^10 = 1*10^1000]
...
Or, in terms of a function,
f(1) = 10^10
f(2) = f(1)^10 = (10^10)^10
f(3) = f(2)^10 = ((10^10)^10)^10
...
Does that match what you want?
Now, please give it some thought. Can you simplify (10^10)^10? Then, can you simplify ((10^10)^10)^10? Then you'll be able to find a formula. The numbers aren't nearly as large as they would be if you had meant 10^(10^(10^...10))) , as I first suggested.