Below are 2 different sequences, but the rules are the same,
2, 3, 3, 9, 9, ?
3, 7, 3, 3, 7, 9, ?
determine the two missing numbers and find the rule,
Bonus. how far can each sequence go? Can you find a longer sequence of numbers that follow the same rule?
the only problem I have with this idea is what dictates
2,3,3,9,9,3
vs
2,3,3,3,3
both of which follow that that the resulting number is prime as suggested
the first I could get to eight digits 23399339 and the second ends at 23333