What do you mean by "teach"? Fundamentally, you have to program.

You should not try to modify the code for Series. If you want different behavior from Series, then you will want to write your own function that behaves like it.

If you know how the series is defined, you can write a function that would give the series to some arbitrary number of terms.

If you aren't sure where to start, try to write a function that behaves like Series for simple examples. Can you generalize it to create the series you are interested in?