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A051995 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+4k, k odd; sequence gives values of r. 8
9, 1, 3, 1, 1, 1, 19, 7, 23, 25, 5, 9, 1, 31, 1, 7, 7, 1, 3, 1, 13, 41, 43, 3, 15, 15, 9, 3, 7, 1, 49, 17, 1, 53, 11, 11, 19, 59, 3, 1, 13, 4, 1, 23, 5, 15, 7, 11, 27, 5, 5, 1, 3, 1, 7, 1, 19, 3, 101, 7, 3, 3, 11, 25, 127, 43, 7, 27, 13, 29, 3, 31, 3, 1, 25, 59, 179, 9, 7, 47, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Excludes discriminants appearing in A051990.
REFERENCES
R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(3), column r.
LINKS
CROSSREFS
Sequence in context: A080504 A327958 A154490 * A198835 A010167 A154181
KEYWORD
nonn,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 12 16:06 EDT 2024. Contains 374251 sequences. (Running on oeis4.)