Help with animation frame data

The Battle Animation Frame Data table (D10141) holds information about which 16x16 tiles any battle animation is going to use, in the form of frames.

Let's take a look at the frame data for the Flail animation (D104B3):

02 0C 12 0D 02 04 12 05 22 06 02 02 12 03 12 0E 22 4C

Each 16x16 tile is made out of two bytes. First byte is the tile's position in the frame and the second one is it's index in the current tile formation (Flail uses a tile formation located at D20940).

Here's a diagram of what these bytes look like, in their order:



As we can see, there are 4 frames being used. Two for the Flail in different positions and two for the swipe effect. Also, the second frame uses 3 tiles (6 bytes), and all the other frames uses 2 tiles (4 bytes). That means that the amount of tiles used in any frame varies. The problem though, is... where is this data at? Where do I find how many tiles is each frame going to use in each animation? I've been messing around with these battle animations for many hours right now, and I still couldn't find this piece of information.