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Interval information
Ratio 2500/2499
Factorization 22 × 3-1 × 54 × 7-2 × 17-1
Monzo [2 -1 4 -2 0 0 -1
Size in cents 0.69263216¢
Name sperasma
FJS name [math]\text{ddd}{-3}^{5,5,5,5}_{7,7,17}[/math]
Special properties square superparticular,
Tenney height (log2 nd) 22.5748
Weil height (log2 max(n, d)) 22.5754
Wilson height (sopfr (nd)) 58
Harmonic entropy
(Shannon, [math]\sqrt{n\cdot d}[/math])
~2.401 bits
Comma size unnoticeable
S-expression S50
open this interval in xen-calc

The sperasma is the 17-limit superparticular comma with a ratio of 2500/2499.

Commatic relations

This comma is the difference between the following superparticular pairs:

Not to mention some nonsuperparticular but useful relations:

It factors into the following superparticular pairs:


Tempering out this comma in the 17-limit results in the rank-6 sperasmic temperament, or in the the subgroup, the rank-4 speric temperament.


The sperasma was named by Aura in 2023. It comes from the Latin verb "spērāre" meaning "to hope" or "to fear"[1].

See also