We've been using Discrete Mathematics and its Applications, by Kenneth Rosen. Cheapest used I see on Amazon is $92. My colleague likes a book by Washburn, Marlowe and Ryan, but it was published in 2000, and I don't see any newer editions online. It looks like it's probably out of print.
I have a few days to pick a textbook. Does anyone know a good one? Are there any open source texts? (I see one they use at UCSD.)
Edited to include the goodies:
- Exeter has a Discrete Math problem set. I'll probably use many of their problems as supplementary material.
- Discrete Math with Ducks, by sarah-marie belcastro, is about $60, and looks pretty good. I've chosen this for my course.
- John Golden pointed out another interesting book, Applied Combinatorics, by Keller and Trotter. Mitch Keller just changed it to a Creative Commons copyright. Thanks, Mitch!