The Specific Harmonicity (Barlow, 1987) of a scale is the square of the number of tones (n) divided by the sum of the absolute values of the reciprocals of the harmonicities of the n*(n-1)/2 non-redundant differences between the n-tones of the set.
See Polansky, 1987, and Chapter 5 [of Divisions of the Tetrachord].
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