**Songs that I write and record.****The paper I wrote for my undergraduate summer research:**A. Hardt & J. M. Troyka. Restricted symmetric signed permutations.*Pure Math. Appl.*, 23: 179–217, 2012.**The paper I wrote for my undergraduate senior thesis:**A. Hardt, P. McNeely, T. Phan, & Justin M. Troyka. Combinatorial species and graph enumeration.

- Lockhart's Lament.
- "On Proof and Progress in Mathematics", by William P. Thurston.
- Math Is Not Linear.
- "The Tau Manifesto" (an improved circle constant: tau is better than pi).
- How to turn a sphere inside-out.
- Sun Zi, the ancient Chinese mathematician who gave us the so-called "Chinese remainer theorem".
- My favorite mathematician, Emmy Noether, a remarkable Jewish woman who was one of the founders of modern algebra.
- An article that gets to the heart of why we use mathematical notation.

- The Online Encyclopedia of Integer Sequences.
- Learn LaTeX.
*Find the Error*, a hilarious compendium of killer calculus questions.