Apparently, this user prefers to keep an air of mystery about them.
11 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
3 DE solution's uniqueness and convexity May 30 '15