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