login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A305416 Negated discriminants of imaginary quadratic number fields whose class group is isomorphic to the Klein 8-group, C_2 x C_2 x C_2. 2
420, 660, 840, 1092, 1155, 1320, 1380, 1428, 1540, 1848, 1995, 3003, 3315 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A046005 and A003644. Note that A003644 = A014602 union A014603 union A192322 union {a(n)} union {5460}. - Jianing Song, Jul 12 2018

LINKS

Table of n, a(n) for n=1..13.

Alexandre Gélin, Everett W. Howe, and Christophe Ritzenthaler, Principally Polarized Squares of Elliptic Curves with Field of Moduli Equal To Q, arXiv:1806.03826 [math.NT], 2018 (see table 1 page 4).

MATHEMATICA

A046005 = Import["https://oeis.org/A046005/b046005.txt", "Table"][[All, 2]];

A003644 = Import["https://oeis.org/A003644/b003644.txt", "Table"][[All, 2]];

A046005 ~Intersection~ A003644 (* Jean-François Alcover, Sep 25 2019 *)

PROG

(PARI) ok(n)={isfundamental(-n) && [2, 2, 2] == quadclassunit(-n).cyc} \\ Andrew Howroyd, Jul 20 2018

CROSSREFS

Cf. A003644, A014602, A014603, A192322.

Subsequence of A046005 and A003644.

Sequence in context: A200521 A189982 A070237 * A156687 A191934 A147775

Adjacent sequences:  A305413 A305414 A305415 * A305417 A305418 A305419

KEYWORD

nonn,fini,full

AUTHOR

Vincenzo Librandi, Jun 12 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 14 12:37 EDT 2021. Contains 343884 sequences. (Running on oeis4.)