The original structure should definitely be called some type of a **list**. I second the opinion that `seq`/`vec`/`arr` implies in-memory linearity. The other expectation that's broken is O(1) access.
If element removal is omitted, the data structure looks more or less trivial and personally I don't see any advantages relying on a list and not on a seq/array as proposed above by @jackhftang and @cblake.
