File format of the pattern design program

This pattern...

...is stored in this file:...

Mønsterfil. Ikkje rediger! 
Storleik:  15
@112222111222211
111122212221111
212112222211212
211211222112112
221121121121122
222112111211222
122211121112221
112221212122211
122211121112221
222112111211222
221121121121122
211211222112112
212112222211212
111122212221111
112222111222211

(The Norwegian text at the top means: Pattern file. Do not edit!)

...and that's it!.