[kzrdude]

That simple sequence, 1, 10, 100 etc, the digit is at least computable in O(1) time which is maybe a good way to look at predictability. It's a simple rule and no effort similar to computing every digit before it is required.

[matvore]

If you store the number of zeros as value z, computing z+1 is O(log n) in the long run for unbounded values of z.