A 7-limit Hexany. This creates a scale of 1 15/14 9/8 135/112 9/7 15/8 2/1, with steps of 15/14 21/20 15/14 16/15 35/24 16/15. With a gap of more than 600 cents on one side, this is an extremely lopsided hexany that does not approximate common practice music at all, but at least the other 5 notes are fairly even in size, making it easy to expand into a usable bihexany.

Circle diagram (rotated).
! 1-7-9-15_Hexany.scl
!
1 7 9 15 2-combination Hexany
6
!
15/14
9/8
135/112
9/7
15/8
2/1

Suggested keyboard mapping: C Db D Eb E B C.