https://www.dotnetzone.gr:443/cs/blogs/birbilis/archive/2011/12/02/combinatorics-library-silverlight-for-windows-phone.aspxI recently found a very nice article at CodeProject on Combinatorics algorithms implementation (specifically Permutations, Combinations and Variations with Repetition option) using C# Generics: http://www.codeproject.com/KB/recipes/Combinatorics.aspxelCommunityServer 2.1 SP3 (Build: 20423.1)