my $numerator = Math::BigFloat->new($rho)->bpow(Math::BigFloat->new($c[$i]));
my $denominator = Math::BigFloat->new(Factorial($c[$i], \@fact))->bmul($G);
printf("numerator: %s\n", $numerator );
printf("denominator: %s\n", $denominator );
my $x = $numerator->copy();
$x->accuracy(10);
print scalar $x->bdiv($denominator), "\n";
$x = $numerator->copy();
$x->accuracy(1000);
print scalar $x->bdiv($denominator), "\n";
exit();

Output:
numerator: 131254331066182.0671680983636563623093384645074900631038196916724632735210716611428572612616761979022584315623777773238891425361932674318752893801
denominator: 200000000000000
1.6   #<--- Way wrong should be around .65