I don't think it has a name - I've always just thought of it as the Riecoin PoW.  To my knowledge, Gatra invented it and it's not been used in this specific form before or since.  (Which is both nice - since it means there's one place to focus mining for finding huge prime clusters - and also a bit of a shame, since it's a fun one.) 

There are some other prime-based currencies, but I don't think any have the same combination of maximally dense 6-tuples, and increasing difficulty by making the numbers larger.   Primecoin, for example, increased diff by finding longer chains, and used Cunningham chains, not dense 6-tuples.

I could suggest some names if you needed, but I think that's really for Gatra to do.