I'm working on a problem that states that:
The Nyström methods have the form:
$$u_{n+r} = u_{n+r-2} + \Delta t \sum_{j=0}^{r}\beta_h f(u_{n+j}).$$
The problem is: Find the two step explicit and implicit Nyström methods and determine their errors.
I did a quick search on Nyström methods but apart from Wikipidea, I coudln't find any beginner's resources on it. Could you please cite me a resource where they detail these and the error analysis as well?