>>310 補足
このデータベース http://galoisdb.math.upb.de/groups?
の中に、下記のSearchのページがあって
それを使うと、最小多項式が出せる
やってみたのが下記の3例

1)は、5次でorder is = 20の例。x^5 - 2とx^5 - 10x^3 + 20x - 4などがある
2)3)は、17次でorder is = 4080とorder is = 16320の場合
 ”Showing 3 matches (no more matches exist in database)”などとある

http://galoisdb.math.upb.de/search
Search
(抜粋)
Specify your search using the fields below. The attributes are presented in a hierarchy (from left to right).
If you don't want to specify an attribute, just leave the field empty (max results per page will default to 1000).

1)
http://galoisdb.math.upb.de/search/display?req=p413
Searchresults
Parameters
Group degree is = 5
order is = 20
Showing 281 matches (no more matches exist in database)
(抜粋)
Group Sigr Discriminant Factorization Polynomial
5T3 5 2450000 24 ・ 55 ・ 72 x^5 - 10x^3 + 20x - 4
5T3 1 50000 24 ・ 55 x^5 - 2

2)
http://galoisdb.math.upb.de/search/display?req=p413
Group degree is = 17
order is = 4080
Showing 3 matches (no more matches exist in database)
(抜粋)
Group Sigr Discriminant Factorization Polynomial
17T6 1 13324913767812132... (27 digits) 230 ・ 1378 x^17 - 3x^16 - 4x^14 + 12x^13 + 24x^12 + 12x^11 - 28x^10 - 90x^9 - 74x^8 + 116x^6 + 132x^5 + 72x^4 + 28x^3 + 12x^2 + 5x + 1

3)
http://galoisdb.math.upb.de/search/display?req=p413
Group degree is = 17
order is = 16320
Showing 5 matches (no more matches exist in database)
(抜粋)
Group Sigr Discriminant Factorization Polynomial
17T8 5 69450042659737600... (33 digits) 228 ・ 518 ・ 714 x^17 + 8x^16 - 24x^15 - 240x^14 + 350x^13 + 2912x^12 - 3724x^11 - 18728x^10 + 29285x^9 + 55120x^8 - 125812x^7 - 11816x^6 + 213248x^5 - 324520x^4 + 431680x^3 - 378416x^2 + 126212x + 4864