The A-155 is by default a 2x8 step sequencer. You would need a pair of sequential switches to use it as a 1x16 step. The manual on the Doepfer website spells put some of the use cases.
-- bopodoq

Omg. Sometimes I think I forget how to read. I've read doepfer documentation first and didn't get it haha.

Thank you very much :)

Sam