>>700
まあ、こういう情報は日本語では少ない。やっぱ英語ですね
で、日本語wikipediaから英語版へ飛んでさぐると、下記のＰＤＦに遭遇
数式処理 Mapleで、Sun Ultrasparc I workstation つかって Ｐ＝101まで計算している
その結論が、table １だ。で、p=23下記に抜粋した。細かく読んでないけど（つまり数値の意味がフォローできていないが）、
p=23辺りから、式が膨大に膨れあがって、サイズ的に紙に書けなくなっている気がするな（＾＾

https://ja.wikipedia.org/wiki/%E5%86%86%E5%88%86%E5%A4%9A%E9%A0%85%E5%BC%8F
円分多項式

https://en.wikipedia.org/wiki/Cyclotomic_polynomial
Cyclotomic polynomial

https://en.wikipedia.org/wiki/Root_of_unity
Root of unity

Notes
6^
https://wikimedia.org/api/rest_v1/media/math/render/svg/c080d78ddb6bf437db6ba043144f8715ad9d86e7
Maple Tech 1999
Solving Cyclotomic Polynomials by Radical Expressions
Andreas Weber and Michael Keckeisen
(抜粋)
Abstract: We describe a Maple package that allows the solution of cyclotomic polynomials by radical
expressions. We provide a function that is an extension of the Maple solve command.

How to Use the Library
The library is included in the file ‘radsolvelib‘. read ‘radsolvelib‘:

Practical Limitations of the Algorithm
Compared to [2] the implementation of the main algorithm
has been optimized. For results in Table 1 we applied radsolve on all cyclotomic polynomials of (prime) degree up to 101 on a Sun Ultrasparc I workstation.

Table 1: Summary of Computations
The following computations times refer to our Maple implementation of the algorithm on a Sun Ultrasparc I workstation.

p＝23
p-1＝2・11
comp.time (in sec.) 34
size of term (tree rep.)
rational operations 7941 radical operations 442

size of term (dag rep.)
rational operations 323 radical operations 5