The sequence 2-7-5 3-2-5 corresponds to (in MHz) you need to tune the Cryptographic Sequencer to, in order to decode Riddler’s broadcast.
This is a reference to the Riddler side mission in Batman: Arkham City . batman arkham city decode broadcast 2-7-5 3-2-5
If you want, I can also tell you that broadcast leads you in the game. The sequence 2-7-5 3-2-5 corresponds to (in MHz)