Base 42 to Base 21

Base 42

In base 42, each digit position represents a power of 42: the rightmost digit counts individual ones, the next counts groups of 42, the next counts groups of 42×42, and so on — the same place-value idea as base 10, just with 42 distinct digits instead of ten.

Base 21

Base 21 works the same way: the rightmost digit counts ones, the next counts groups of 21, the next counts groups of 21×21, and so on, using 21 distinct digits.