Bits Collision
set  odds (2**32 bits)
---  ---------
1e3    0.01%
1e4    1.16%
1e5   68.8%
1e6  100% (to about 50 digits of accuracy)

##</code><code>##

use Math::BigApprox 'c';
my $bits = 2**32;
my $inserts = 1e5;
print 1-(c($bits-$inserts)^c($bits-1))/c($bits)**$inserts, $/;

##</code><code>##

Odds  Inserts
----  -------
  1%  ~28e6
 10%  ~45e6
 50%  ~65e6
 90%  ~83e6
 99%  ~96e6