
Combinatorics of parentheses and binary operators
Combining parentheses and binary operators to calculate arithmetic properties, and reasoning about their recurrence relations and generic closed forms.

Generating random data, part 2
Given various sources of random data on a Unix system, which are the most efficient while also producing sufficiently random data?

Generating random data, part 1
Why are computers so bad at behaving unpredictably, and how can we generate random data effectively?

Fixed points of hash functions
Under what circumstances can (or must) a fixed point of a cryptographic hash function exist: where a string hashes to itself?

Mathematical quines
A demonstration of a mathematical quine: a formula which prints itself when graphed.

The Monty Hall Problem
The somwhat counterintuitive Monty Hall Problem, and a quick mathematical explanation and generalisation.

Hangman strategy
The best strategy to use when choosing words in Hangman, depending on the number of guesses allowed and the length of the word.