Motivating sequences

Students are frequently -very- resistant to looking at sequences for
limits -- they want to look at the graph.

This is especially true for approaching a point from both side (in 1
dimension).

A humor way to describe this (when approaching a finite point)
is that there's an "epileptic frog" trying to reach a point, and keeps
over-shooting it and such.

NB:
To convince 'em that maybe sequences are a good idea,
giving 'em a function that you -can't- graph should be compelling, but
probably isn't.