1-3-5-9 by 11/9 bihexany
An 11-limit Bihexany. This creates a scale of 1 55/54 9/8 55/48 11/9 5/4 11/8 3/2 55/36 5/3 11/6 15/8 2/1, with steps of 55/54 243/220 55/54 16/15 45/44 11/10 12/11 55/54 12/11 11/10 45/44 16/15. This expands the near-diatonic scale of the base hexany into a 12 note scale with 8 perfect fifths which adds plenty of neutral harmonies to your options, although it is not particularly optimal melodically due to the many steps of 55/54. This is because both the offset interval and the 5-limit intervals are slightly flatter than steps of 24edo, so their flatness combines, and offset intervals like 11/8 and 33/32 will give slightly better results overall.
! 1-3-5-9_by_11/9_Bihexany.scl ! 1 3 5 9 by 11/9 2-combination Bihexany 12 ! 31.766 203.910 235.676 347.407 386.313 551.317 701.955 733.721 884.358 1049.362 1088.268 1200