On page 24 of the Illuminatus! trilogy, the computer programmed with the I Ching and other forecasting methods and data issues Hexagram 23, Breaking Apart.
It was not the first time the I Ching has been used in a work of fiction. As Ted Hand has pointed out, it likely was first used in a novel in Philip K. Dick's The Man in the High Castle, which I've been re-reading. (Just as when I first read it as a teenager, I'm struck by how great it is.) In the first three chapters, Dick's characters consult the I Ching several times. Hand has just posted a link to the text of the I Ching that Dick used.
Just for fun, I decided to try the online version of the I Ching. I asked it, "What does the future hold for the RAWIllumination.net blog?"
I got Hexagram 20, "Contemplation."
20 - Twenty
Kuan / Contemplation
The gentle Wind roams the Earth:
The Superior Person expands his sphere of influence as he expands his awareness.
Deeply devoted to his pursuit of clarity and wisdom, he is unconscious of the inspiring, positive example he is setting for others to emulate.
You have cleansed yourself; now stand ready to make your humble, devout offering.
The situation marks a rising to new heights.
As you climb for a better view of the panorama, you make yourself more conspicuous to those below.
This hexagram is also known as the Watchtower, because the shape formed by its lines resembles the ancient guardposts manned by Chinese soldiers.
These towers were placed on mountainsides to give a better vantage point.
To those below, the watchtowers served as landmarks to help them find their way.
The quality of your search for clarity in this situation serves as such a guidepost for others along the Way.
The "Dick text's" version of my hexagram is here.