How Many Different Unlock Patterns Could You Create?

The Android pattern lock screen consists of 9 contact points arranged in a 3 x 3 matrix. Acceptable patterns are conditioned by three main rules...

1. A minimum of four contact points must be connected, and the maximum number is obviously 9.
2. A contact point can only be used once!
3. An intermediate point between two connected points, must be included in the pattern order, unless it was previously used!

So how many different combinations are possible on the pattern lock screen? Under the conditions created by these rules you can create a total of 389,112 different patterns!

(vía: CHM Tech)