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A343690
Minimal value of positive discriminants of number fields of degree n.
3
1, 5, 49, 117, 1609, 28037, 612233, 1257728
OFFSET
1,2
COMMENTS
Conjecture: a(n) < A343772(n) for n == 0, 1 (mod 4), a(n) > A343772(n) for n == 2, 3 (mod 4).
FORMULA
A006557(n) = Min_{a(n), A343772(n)}.
EXAMPLE
The number field F of degree n whose discriminant is positive and of minimal value:
n = 2, F = Q[x]/(x^2 - x - 1), d = 5;
n = 3, F = Q[x]/(x^3 - x^2 - 2x + 1), d = 49;
n = 4, F = Q[x]/(x^4 - x^3 - x^2 + x + 1), d = 117;
n = 5, F = Q[x]/(x^5 - x^3 - x^2 + x + 1), d = 1609;
n = 6, F = Q[x]/(x^6 - 2x^5 + 3x^3 - 2x - 1), d = 28037;
n = 7, F = Q[x]/(x^7 - x^6 + x^5 - x^3 + x^2 - x - 1), d = 612233;
n = 8, F = Q[x]/(x^8 - 2x^7 + 4x^5 - 4x^4 + 3x^2 - 2x + 1), d = 1257728.
CROSSREFS
Cf. A343772 (the negative discriminant case), A006557 (the overall case).
Sequence in context: A298580 A299572 A266127 * A298394 A299512 A183333
KEYWORD
nonn,hard,more
AUTHOR
Jianing Song, Apr 26 2021
STATUS
approved