X ( 1 , 13 , 2 , 12 ) X ( 2 , 24 , 3 , 23 ) X ( 3 , 35 , 4 , 34 ) X ( 7 , 19 , 8 , 18 ) X ( 8 , 30 , 9 , 29 ) X ( 9 , 41 , 10 , 40 ) X ( 13 , 25 , 14 , 24 ) X ( 14 , 36 , 15 , 35 ) X ( 15 , 5 , 16 , 4 ) X ( 19 , 31 , 20 , 30 ) X ( 20 , 42 , 21 , 41 ) X ( 21 , 11 , 22 , 10 ) X ( 25 , 37 , 26 , 36 ) X ( 26 , 6 , 27 , 5 ) X ( 27 , 17 , 28 , 16 ) X ( 31 , 1 , 32 , 42 ) X ( 32 , 12 , 33 , 11 ) X ( 33 , 23 , 34 , 22 ) X ( 37 , 7 , 38 , 6 ) X ( 38 , 18 , 39 , 17 ) X ( 39 , 29 , 40 , 28 ) {\displaystyle X(1,13,2,12)X(2,24,3,23)X(3,35,4,34)X(7,19,8,18)X(8,30,9,29)X(9,41,10,40)X(13,25,14,24)X(14,36,15,35)X(15,5,16,4)X(19,31,20,30)X(20,42,21,41)X(21,11,22,10)X(25,37,26,36)X(26,6,27,5)X(27,17,28,16)X(31,1,32,42)X(32,12,33,11)X(33,23,34,22)X(37,7,38,6)X(38,18,39,17)X(39,29,40,28)}
