The "Ode-to-Napoleon" hexa chord is the six-member set-class with the highest number of interval classes 3 and 4[8] yet lacks 2s and 6s.[2] 6-20 maps onto itself under transposition three times (@0,4,8) and under inversion three times (@1,4,9) (six degrees of symmetry), allowing only four distinct forms, one form overlapping with another by way of an augmented triad or not at all, and two augmented triads exhaust the set as do six minor and major triads with roots along the augmented triad.[2] Its only five-note subset is 5-21 (0,1,4,5,8), the complement of which is 7-21 (0,1,2,4,5,8,9), the only superset of 6-20.[9] The only more redundant hexachord is 6-35.[2] It is also Ernő Lendvai's "1:3 Model" scale and one of Milton Babbitt's six all-combinatorial hexachord "source sets".[2]
Baker, James M. (1986). The Music of Alexander Scriabin, p. 214. New Haven: Yale University Press. ISBN0-300-03337-0. Cited in Van den Toorn (1996), pp. 128–129.