== Concrete Mathematics ==
=== In finding a closed-form expression for some quantity of interest like T<sub>n</sub> we go Through three stages. ===
1. Look at small cases. This gives us insight into the problem and helps us in stages 2 and 3.
2. Find and prove a mathematical expression for the quantity of interest. (Induction so on..)
3. Find and prove a closed form for our mathematical expression.

=== Sample problem ===
==== Recurrent Problems ====
[The Tower of Hanoi]
[Lines In The Plane]

=== Guestbook ===