b21 := (1,3,6,11,19,30,47)(2,4,8,14,24,36,58)(5,9,16,26,40,63,85)(7,12,21,32,
     51,43,67)(10,17,27,42,66,90,107)(13,22,33,53,68,92,70)(15,25,38,61,65,88,
     104)(18,28,44,69,93,86,101)(20,31,49,76,97,113,117)(23,34,55,79,99,115,
     109)(29,45,71,37,59,80,54)(35,56,81,100,112,106,118)(41,64,87,102,116,57,
     62)(46,72,95,110,119,125,78)(48,74,82,89,105,94,108)(52,73,96,111,121,77,
     60);