I am going to keep adding to this post for a while, so if interested look later and there will be more threads.
1) Mellie special
http://web2.0calc.com/questions/let-the-term-s_n-be-the-sum-of-the-first-n-powers-of-2-for-instance-s_3-2-0-2-1-2-2-7-find-the-largest-possible-value-of
3) Fiora's question
http://web2.0calc.com/questions/act-preblem
+118608 
