It’s a fun task to generate these from the five base shapes.
Another number system, which I learned about recently on HN, are the Kaktovik numerals, which are even closer to D'ni. Interestingly, they were developed just a couple of years before Riven was released.
https://en.wikipedia.org/wiki/Kaktovik_numerals
It's not a base-5 system exactly. It's base-20, where the rotated-and-superimposed digit is only one of the first three numerals. I guess you could call it a mixed-radix system, where the bases alternate like 4 5 ... 4 5 4 5 and where each group of 4 5 combines into a single symbol.
D'ni numerals overlay two base-5 values in the same space, one horizontal & the other vertical, to represent 0–24. There's even a one-character numeral for 25, though it rarely comes up in-game. Different, of course, but I wouldn't be surprised if Cistercian was the inspiration.
[1] https://www.omniglot.com/conscripts/dni.htm
[2] https://dni.fandom.com/wiki/D'ni_Numerals