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