I remembered there was some kind of "more efficient" coin system. I searched for "ternary coins" and "radix coins". Both are some crypto scams. Fun times.

Apparently I misremembered how it worked and it's actually 1, 5, 18 and 25 (or 29) for a 4 coin system: https://cs.uwaterloo.ca/~shallit/Papers/change2.pdf