| n - 3 | n - 2 | n - 1 |   n   | n + 1 | n + 2 | n + 3 |
4n   |                   1       2       1        
4n+1 |                   1       1       2
4n+2 |                           2       2        
4n+3 |                           2       1       1

                         2       7       6       1 = 16


            1         2         3
   0123456789012345678901234567890

 1 31
 2 22
 3 211
 4 121
 5 112
 6  22
 7  211
 8  121
 9  112
10   22
11   211
12   121
13   112
14    22