1666/1665

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Interval information
Ratio 1666/1665
Subgroup monzo 2.3.5.7.17.37 [1 -2 -1 2 1 -1
Size in cents 1.039468¢
Name gentisma
Color name 37u17ozzg2
thisusozozogu 2nd
FJS name [math]\text{dd3}^{7,7,17}_{5,37}[/math]
Special properties superparticular,
reduced
Tenney height (log2 nd) 21.4035
Weil height (log2 max(n, d)) 21.4043
Wilson height (sopfr(nd)) 81
Harmonic entropy
(Shannon, [math]\sqrt{nd}[/math])
~1.2092 bits
Comma size unnoticeable
open this interval in xen-calc

1666/1665, the gentisma, is a 37-limit superparticular comma of about 1.04 cents.

Commatic relationships

This comma is the difference between the following superparticular pairs:

It can be factored into the following superparticular intervals:

Temperaments

Tempering out this comma in the full 37-limit leads to the rank-11 temperament gentismic. Using the 2.3.5.7.17.37 subgroup leads to the rank-5 temperament gentic.

Gentic

Subgroup: 2.3.5.7.17.37

Comma list: 1666/1665

Mapping:

[⟨ 1 1 2 2 4 5 ],
0 1 0 0 0 -2 ],
0 0 1 0 0 -1 ],
0 0 0 1 0 2 ],
0 0 0 0 1 1 ]]

Optimal tuning (CTE): ~2 = 1\1, ~3/2 = 702.013, ~5/4 = 386.375, ~7/4 = 968.645, ~17/16 = 104.764

Optimal ET sequence5g, 7dgll, 8d, 9, 10, 12, 19gl, 19, 22, 27g, 31l, 39dgl, 41gl, 49gl, 50, 58, 60l, 68, 72, 99, 171, 311, 400, 472, 482, 571, 711, 882

Etymology

This comma was named by Francium in 2025. It refers to 1666 van Gent, the asteroid, which in turn was named after Hendrik van Gent, a Dutch astronomer.

See also