  Let G be a two generator subgroup of PSL(2,C). The Jorgensen number J(G) of G
is defined by
  J(G)=inf{ |tr^2 A-4|+|tr[A,B]-2| ; G=<A,B>}.
  If G is a non-elementary Kleinian group, then J(G) >= 1. This inequality is
called Jorgensen's inequality. In this paper, we show that, for any r >= 1,
there exists a non-elementary Kleinian group whose Jorgensen number is equal to
r. This answers a question posed by Oichi and Sato. We also present our
computer generated picture which estimates Jorgensen numbers from above in the
diagonal slice of Schottky space.
