How do I code this?

[Lopyt]

For the 8bit saw I would like to add a unison effect, where 3 versions of the sound are played at the same time but each have a pitch that is slightly flat, so A would be 440Hz, 438Hz, and 442Hz, or similar to that. I want to separate the notes by the same % of a semitone for every note though. Is there a way I can do this with Console?