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A051997 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+2k, k odd; sequence gives values of k. 8
-1, 1, 1, 3, 1, -1, 1, -3, 1, -1, -5, 3, 1, -1, -3, 3, -5, 1, 5, -3, 3, 7, -1, -1, -3, -5, -1, 1, 5, 1, -7, -1, 7, 1, -5, 1, -1, 3, 5, 1, 3, -3, 13, 5, 3, 1, -15, -5, 3, -7, 7, -3, 3, 13, -3, -11, 3, -15, 1, -1, -21, -33, 15, 3, -3, -5, 5, -17, 7, 3, 5, 1, -5, 7, 3, -13 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
COMMENTS
Excludes discriminants appearing in A051990.
REFERENCES
R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(2), column k.
LINKS
CROSSREFS
Sequence in context: A155828 A226203 A327791 * A155744 A086869 A348953
KEYWORD
sign,fini,full
AUTHOR
N. J. A. Sloane, Jan 04 2000
EXTENSIONS
Offset changed to 1 by Georg Fischer, Sep 21 2021
STATUS
approved

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Last modified July 13 01:42 EDT 2024. Contains 374259 sequences. (Running on oeis4.)