1323/1280

Interval information

Ratio	1323/1280
Factorization	2-8 × 33 × 5-1 × 72
Monzo	[-8 3 -1 2⟩
Size in cents	57.2031¢
Names	septimal 2/7-tone, septimal 21st-octave
Color name	Lzzg2, lazozogu 2nd
FJS name	[math]\displaystyle{ \text{m2}^{7,7}_{5} }[/math]
Special properties	reduced
Tenney height (log2 nd)	20.6915
Weil height (log2 max(n, d))	20.7392
Wilson height (sopfr(nd))	44
Harmonic entropy (Shannon, [math]\displaystyle{ \sqrt{nd} }[/math])	~4.41258 bits
Comma size	medium
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1323/1280, the septimal 2/7-tone, is a 7-limit ratio very close to the step of 21edo.

Theory

If taken as a comma to be tempered, it produces greenwood. If it is taken as a period and assigned to 1\21 of the octave, it serves as a period in the akjayland temperament.

[-169 63 -21 42⟩ is a comma that results from the difference of 21 instances of this interval with the octave. For EDOs N up to ~5000, it is tempered out if and only if 21 divides N.