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A329182
Negative discriminants with form class group isomorphic to C_2 X C_2 (negated).
3
84, 96, 120, 132, 160, 168, 180, 192, 195, 228, 240, 280, 288, 312, 315, 340, 352, 372, 408, 435, 448, 483, 520, 532, 555, 595, 627, 708, 715, 760, 795, 928, 1012, 1435
OFFSET
1,1
COMMENTS
This sequence is finite and this is the full list.
Equivalently, negative discriminants of orders whose class group is isomorphic to C_2 X C_2 (negated). - Jianing Song, May 17 2021
LINKS
Rick L. Shepherd, Binary quadratic forms and genus theory, Master of Arts Thesis, University of North Carolina at Greensboro, 2013
PROG
(PARI) isA329182(d) = (d>0) && ((d%4==0)||(d%4==3)) && quadclassunit(-d)[2]==[2, 2] \\ Jianing Song, May 17 2021
CROSSREFS
Cf. A133675 (negative discriminants with form class group isomorphic to the trivial group), A322710 (isomorphic to C_2), A328825 (isomorphic to C_3), this sequence (isomorphic to C_2 X C_2), A330219 (isomorphic to C_4).
The fundamental terms are listed in A192322. Cf. also A013658.
Sequence in context: A045569 A219183 A289218 * A113931 A352230 A214866
KEYWORD
nonn,fini,full
AUTHOR
Jianing Song, Dec 05 2019
STATUS
approved