(2n-1)/2
My answer is ...
所有跟帖:
• Explanation..... -Commentate- ♂ (315 bytes) () 11/11/2010 postreply 10:01:53
• 回複:Explanation..... -wushuihe- ♂ (68 bytes) () 11/11/2010 postreply 17:50:48
• how about n=1?....n is right -jinjing- ♀ (0 bytes) () 11/11/2010 postreply 16:03:20