MathJax would be handy for formatting things like the formulas in the following abstract:
We analyze the most commonly used method for shuffling cards. The main result is a simple expression for the chance of any arrangement after any number of shuffles. This is used to give sharp bounds on the approach to randomness: $\frac{3}{2} \log_2 n + \theta$ shuffles are necessary and sufficient to mix up $n$ cards. Key ingredients are the analysis of a card trick and the determination of the idempotents of a natural commutative subalgebra in the symmetric group algebra.
Bayer, Dave; Diaconis, Persi. Trailing the Dovetail Shuffle to its Lair. Ann. Appl. Probab. 2 (1992), no. 2, 294--313. doi:10.1214/aoap/1177005705. http://projecteuclid.org/euclid.aoap/1177005705.