When I last reviewed the writeup for the series operators, I noticed two issues:
First, why is the RHS argument a list? You only ever use the first
element of it; so why don't you just reference a single value?
Second, I'm trying to think of a simple and intuitive way to write up
a series expression for:
triangle numbers: 0, 1, 3, 6, 10, 15, 21, etc.
square numbers: 0, 1, 4, 9, 16, 25, 36, etc.
factorials: 1, 1, 2, 6, 24, 120, 720, 5040, etc.
The difficulty that I'm running into is that there's no reasonably
straightforward way of computing a given term solely from the previous
one or two items in the list. There _is_ a simple way to compute the
next item from the previous item and the index number, or even
strictly from the index number; but there is no way that I'm aware of
to get the index number into the step function.
Jonathan "Dataweaver" Lang