1) $f_{n}$ can be computed by polynomial size randomized read-once ordered branching program with a small one-sided error;
2) $f_{n}$ cannot be computed in polynomial size by deterministic read-once branching programs;
3) $f_{n}$ cannot be computed in polynomial size by deterministic
read-$k$-times ordered branching program for $k=o(n/\log n)$
(the required deterministic size is
$\exp\left(\Omega\left(\frac{n}{k}\right)\right)$).
Paper Available at:
ftp://dimacs.rutgers.edu/pub/dimacs/TechnicalReports/TechReports/1996/96-46.ps.gz