Apparently, this user prefers to keep an air of mystery about them.
10 A question related to Pigeonhole Principle mar 4 '13
7 Combinatorial proof to $n! = (n-1)[(n-1)! + (n-2)!]$ mar 25 '13
5 Creating a sequence that does not have an increasing or a decreasing sequence of length 3 from a set with 5 elements feb 27 '13