  In order to avoid unnecessary applications of Miller-Rabin algorithm to the
number in question, we resort to trial division by a few initial prime numbers,
since such a division take less time.
  How far we should go with such a division is the that we are trying to answer
in this paper?For the theory of the matter is fully resolved. However, that in
practice we do not have much use.
  Therefore, we present a solution that is probably irrelevant to theorists,
but it is very useful to people who have spent many nights to produce large
(probably) prime numbers using its own software.
