Tricky Google interview question

Question

A friend of mine is interviewing for a job. One of the interview questions got me thinking, just wanted some feedback.

There are 2 non-negative integers: i and j. Gi

Answer 1

You have to keep track of the individual exponents of them, and what their sums would be

so you start with f(0,0) --> 1 now you have to increment one of them:

f(1,0) = 2
f(0,1) = 5

so we know 2 is the next - we also know we can increment i's exponent up until the sum surpases 5.

You keep going back and forth like this until you're at your deisred number of rounds.