X ( 2 , 16 , 3 , 15 ) X ( 4 , 17 , 5 , 18 ) X ( 6 , 2 , 7 , 1 ) X ( 8 , 3 , 9 , 4 ) X ( 10 , 6 , 11 , 5 ) X ( 12 , 19 , 13 , 20 ) X ( 14 , 7 , 15 , 8 ) X ( 16 , 10 , 17 , 9 ) X ( 18 , 13 , 19 , 14 ) X ( 20 , 11 , 1 , 12 ) {\displaystyle X(2,16,3,15)X(4,17,5,18)X(6,2,7,1)X(8,3,9,4)X(10,6,11,5)X(12,19,13,20)X(14,7,15,8)X(16,10,17,9)X(18,13,19,14)X(20,11,1,12)}
