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.

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

Offset: 1

Author

N. J. A. Sloane, Jan 04 2000

Keywords

• nonn
• fini
• full

Comments

Excludes discriminants appearing in A051990.

References

• R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(3), column r.

Crossrefs

Cf. A051990, A051991, A051992, A051993, A051994, A051996, A051997, A051998.

Extensions

Offset changed to 1 by Georg Fischer, Sep 21 2021