  We have calculated numerically geometrical means of the denominators of the
continued fraction approximations to the Brun constant B2. We get values close
to the Khinchin constant. Next we calculated the n-th square roots of the
denominators of the n-th convergents of these continued fractions obtaining
values close to the Khinchin-Levy constant. These two results suggests that B2
is irrational, supporting the common believe that there is an infinity of
twins.
