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A192322 Negated discriminants of imaginary quadratic number fields whose class group is isomorphic to the Klein 4-group, C2 x C2. 4
84, 120, 132, 168, 195, 228, 280, 312, 340, 372, 408, 435, 483, 520, 532, 555, 595, 627, 708, 715, 760, 795, 1012, 1435 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Added keyword "full" - This sequence is a subsequence of A013658, whose last term is 1555. I have verified that the terms above are complete and correct. - Rick L. Shepherd, May 06 2013

LINKS

Table of n, a(n) for n=1..24.

Alexandre GĂ©lin, 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).

Rick L. Shepherd, Binary quadratic forms and genus theory, Master of Arts Thesis, University of North Carolina at Greensboro, 2013.

PROG

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

CROSSREFS

Subsequence of A013658.

Sequence in context: A316833 A316834 A227734 * A015708 A114822 A099637

Adjacent sequences:  A192319 A192320 A192321 * A192323 A192324 A192325

KEYWORD

nonn,fini,full

AUTHOR

David Terr, Jun 28 2011

STATUS

approved

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Last modified July 13 17:54 EDT 2020. Contains 335689 sequences. (Running on oeis4.)