 The same random order is also characteristic for the alternation of the lengths of successive eras (by era length, BKL understand the number of Kasner epoch that an era contains, and not a time interval).To each era ("s"-th era) correspond a series of values of the parameter "u" starting from the greatest, formula_46, and through the values formula_46 − 1, formula_46 − 2, ..., reaching to the smallest, formula_49 < 1.Then
that is, "k"("s") = [formula_46] where the brackets mean the whole part of the value.