Base 15 to Base 42

Base 15

In base 15, each digit position represents a power of 15: the rightmost digit counts individual ones, the next counts groups of 15, the next counts groups of 15×15, and so on — the same place-value idea as base 10, just with 15 distinct digits instead of ten.

Base 42

Base 42 works the same way: the rightmost digit counts ones, the next counts groups of 42, the next counts groups of 42×42, and so on, using 42 distinct digits.