2: 1
3: 2
4: 3
5: 4
6: 5
7: 6
8: 5
9: 4
10: 3
11: 2
12: 1

 2: *
 3: **
 4: ***
 5: ****
 6: *****
 7: ******
 8: *****
 9: ****
10: ***
11: **
12: *

                                 
                                 
                *                
             *  *  *             
          *  *  *  *  *          
       *  *  *  *  *  *  *       
    *  *  *  *  *  *  *  *  *    
 *  *  *  *  *  *  *  *  *  *  * 
 2  3  4  5  6  7  8  9 10 11 12