21 is a pair of symbols, usually from a limited base set of ten. Each of them, 2 and 1, were previously used singly, and are subsequently recycled by being put together to designate yet another number in accordance with a rule. My point about base infinity is that we'd never get this. Every number would have a brand new single symbol that's specially invented or arbitrarily chosen for it rather than formed from a combination of old ones, and so in that sense the symbol would not be determined by what's gone before.

An absurd situation in practical terms, however I don't know enough of mathematical chaos theory to say if that makes such a sequence chaotic. That was the question I was putting to the (other?) anonymous contributor to this thread, and to anyone else.

Chris G