Most of the time, when I can’t figure out a formula or an equation, it’s because I’ve made a mistake somewhere along the line. But every once in a while, the mistake is in the book itself!

Here are some typos and mistakes I’ve found in various textbooks that are still in print but are not being updated (and so don’t currently have an errata page elsewhere on the web). If you have something to add, feel free to send me a note.

- Maxwell Rosenlicht, “Introduction to Analysis”: the decimal representation on the bottom of page 26 is incorrect for the case when a_0 is a negative integer. For example, the negative number -5.12 is usually understood as being (- 5 – 1/10 – 2/100) and
**not**(- 5 + 1/10 + 2/100).

- Peter Schumer, “Introduction to Number Theory”.
- page 152, problem 1(b): replace 1/(n+1)2 with 1/(n+1)^2 in the formula.
- bottom of page 128: replace 355/133 with 355/113.

- Arthur Benjamin and Jennifer Quinn, “Proofs that really COUNT”.
- page 78, identity 153, replace that last binomial coefficient, “n-3 choose 3”, with 2^(n-3).
- page 165, hint for identity 154, replace “… two distinct
*ordered*pairs …” with “… two distinct pairs*of distinct elements*…”.