Just leaving myself a reminder to com back here.

9 to 3 through 12 unlocks the rest of the numbers.

Don't be afraid to add spaces.

333

666

999

12 12 12

3—3—3

9

15 15 15

6—6—6

18

9

18 18 18

9—9—9

27

9

21 21 21

3—3—3

9

If you leave them single, you get 3,6,9, 3, 6, 9,…

I'll let you extrapolate from there.