OFFSET
1,2
COMMENTS
B. Matschke showed that a(11) = 340618 assuming the Generalized Riemann Hypothesis.
LINKS
K. Belabas, A fast algorithm to compute cubic fields, Math. Comp. 66 (1997), no. 219, 1213-1237.
J. W. Jones and D. P. Roberts, A database of number fields, LMS J. Comput. Math. 17 (2014), no. 1, 595-618.
B. Matschke, Number fields unramified outside S.
EXAMPLE
For n = 1, there are no cubic number fields unramified away from 2, so a(1) = 0.
For n = 2, the a(2) = 9 cubic number fields unramified away from {2,3} can be given by Q(a) where a is a root of x^3 - 3x - 1, x^3 - 2, x^3 + 3x - 2, x^3 - 3, x^3 - 3x - 4, x^3 - 3x - 10, x^3 - 12, x^3 - 6, or x^3 - 9x - 6.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robin Visser, Nov 26 2023
STATUS
approved