b21 := (1,2,5,12,25,37,19,9,3)(4,10,21,41,69,54,31,15,7)(6,14,29,51,82,55,32,
     16,8)(11,22,43,73,90,57,33,17,23)(13,27,50,81,91,58,34,18,28)(20,38,65,
     99,118,83,52,30,39)(24,44,75,111,93,60,35,59,45)(26,48,80,117,94,62,36,
     61,49)(40,66,100,132,122,88,56,87,67)(42,70,104,137,119,85,53,84,71)(46,
     76,113,130,96,63,95,114,77)(47,78,115,131,98,64,97,116,79)(68,101,133,
     153,127,92,126,134,102)(72,105,138,150,124,89,123,139,106)(74,108,142,
     149,121,86,120,143,109)(103,135,158,156,129,112,147,159,136)(107,140,160,
     155,128,154,148,161,141)(110,144,162,152,125,151,165,157,145)(146,163,
     164);