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