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A359296
Absolute discriminants of imaginary quadratic fields with elementary bicyclic 7-class group and capitulation type the identity permutation.
2
4973316, 5073691
OFFSET
1,1
COMMENTS
An algebraic number field with this capitulation type has a 7-class field tower of precise length 2 with Galois group isomorphic to the Schur sigma-group SmallGroup(16807,7). It is a solution to the problem posed by Olga Taussky-Todd in 1970.
LINKS
D. C. Mayer, The distribution of second p-class groups on coclass graphs, J. Théor. Nombres Bordeaux 25 (2013), no. 2, 401-456. Sec. 3.5.4, p. 450.
D. C. Mayer, The distribution of second p-class groups on coclass graphs, arXiv:1403.3833 [math.NT], 2014.
O. Taussky-Todd, A remark concerning Hilbert's Theorem 94, J. reine angew. Math. 239/240 (1970), 435-438.
EXAMPLE
The second, respectively first, imaginary quadratic field with 7-class group (7,7) and identity capitulation (12345678) has discriminant -5073691, respectively -4973316, and was discovered by Daniel C. Mayer on 26 October 2019, respectively 09 November 2019. It has ordinal number 555, respectively 545, in the sequence of all imaginary quadratic fields with 7-class group (7,7).
CROSSREFS
Cf. A359291.
Sequence in context: A157804 A151646 A210318 * A227155 A106785 A034607
KEYWORD
nonn,more,hard,bref
AUTHOR
STATUS
approved