How to Graph a Web Plot on the TI84 Plus
Web plots are a really interesting representation of the behavior of a recursive sequence, and you can use the TI84 Plus to graph web plots. Web plots actually look a little like spider webs. Following are a few ground rules when working with web plots:

Sequence must be recursive: The sequence is required to have one level of recursion u(n–1); using u(n–2) is not allowed.

Sequence cannot reference n directly.

Sequence cannot reference any defined sequence except itself.
Here, you use the recursive sequence, a_{n} = –1/2(a_{n–1}), where a_{1} = 8.
Here are the steps to enter and graph a web plot in your calculator:

Press [2nd][ZOOM] to access the Format menu.

Use the arrow keys to navigate your cursor to Web in the top row and press [ENTER].

Press [Y=] to access the Y= editor.

Enter the recursive formula for u(n).
Use u(n–1) for the previous term.

Enter u(nMin).
Enter the initial term in the sequence as shown in the first screen.

Press [ZOOM][6].
If you aren’t sure what the graph of the web plot will look like, a ZStandard graphing window is a good place to start, as shown in the second screen.
The line graphed at y = x is not part of the web plot; it is called the reference line.

Press [TRACE] and press the rightarrow key repeatedly to draw the web.
See the third screen. The web plot helps you see that this sequence converges.
To clear a webplot, press [2nd][PRGM][ENTER].