SSD(18, 3^12) via Theorem 8 (n=3, s=3, k=2)

0 0 0 0 0 0 0 0 0 0 0 0
0 1 1 1 0 1 1 1 0 1 1 1
0 2 2 2 0 2 2 2 0 2 2 2
1 0 1 2 1 0 1 2 1 0 1 2
1 1 2 0 1 1 2 0 1 1 2 0
1 2 0 1 1 2 0 1 1 2 0 1
2 0 2 1 2 0 2 1 2 0 2 1
2 1 0 2 2 1 0 2 2 1 0 2
2 2 1 0 2 2 1 0 2 2 1 0
0 0 0 0 1 1 1 1 2 2 2 2
0 1 1 1 1 2 2 2 2 0 0 0
0 2 2 2 1 0 0 0 2 1 1 1
1 0 1 2 2 1 2 0 0 2 0 1
1 1 2 0 2 2 0 1 0 0 1 2
1 2 0 1 2 0 1 2 0 1 2 0
2 0 2 1 0 1 0 2 1 2 1 0
2 1 0 2 0 2 1 0 1 0 2 1
2 2 1 0 0 0 2 1 1 1 0 2

Note: The overall A2 value is 6. 
  The possible projected A2 values are 0 and 1/2 with frequencies 54 and 12.