Find an example of two sequences $\{x_n\}$ and $\{y_n\}$ such that $R(x_n) = R(y_n)$ and:
- $x_n$ and $y_n$ are convergent, and $\lim_{n \to \infty} x_n \ne \lim_{n \to \infty} y_n$;
- $x_n$ converges and $y_n$ diverges.
Here $R(x)$ denotes the set of all possible values of the sequence. Roughly speaking $y_n$ is a permutation of $x_n$ (at least as far as I understood it).
For the first case I was thinking of such a function which would have the same range. For example consider the following sequences:
$$ f(x) = \arcsin\left(\frac{x-2}{x-1}\right) \\ y(x) = \arcsin\left(-\frac{x-2}{x-1}\right) $$
Clearly both of them have the same range of values but their limits are different. The problem is that replacing $x$ with $n$ breaks continuity and we get this.
Second case is unclear to me.
Could we find some sequences satisfying $(1)$ and $(2)$?
No need to consider such complicated functions. For (1), just take $$ (x_n)_{n=1}^\infty = (1,0,0, 0,\ldots), \quad (y_n)_{n=1}^\infty = (0,1,1,1,\ldots), $$ and for (2), keep the same $(x_n)$ and take $$ (y_n)_{n=1}^\infty = (1,0,1,0,\ldots). $$