  The recent discovery of a non-zero value of the mixing angle theta_13 has
ruled out tri-bimaximal mixing as the correct lepton mixing pattern generated
by some discrete flavor symmetry (barring large next-to-leading order
corrections in concrete models). In this work we assume that neutrinos are
Majorana particles and perform a general scan of all finite discrete groups
with order less than 1536 to obtain their predictions for lepton mixing angles.
To our surprise, the scan of over one million groups only yields 3 interesting
groups that give lepton mixing patterns which lie within 3-sigma of the current
best global fit values. A systematic way to categorize such groups and the
implications for flavor symmetry are discussed.
