A051993 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+k, k odd; sequence gives values of r.

3, 4, 5, 1, 6, 2, 1, 8, 3, 2, 2, 1, 11, 12, 13, 1, 14, 2, 1, 5, 3, 16, 17, 6, 19, 4, 1, 22, 22, 23, 2, 2, 10, 2, 1, 31, 34, 34, 2, 1, 5, 7, 36, 37, 2, 1, 13, 8, 8, 1, 14, 9, 2, 46, 47, 16, 3, 4, 56, 3, 2, 58, 20, 12, 2, 3, 2, 23, 10, 2, 24, 73, 5, 4, 2, 16, 2, 4, 8, 8, 19, 98, 20, 2, 2, 4, 24, 11, 122, 4, 4, 142, 26, 68, 242, 278, 22, 32

Offset

1,1

References

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(1), column r.

Links

Table of n, a(n) for n=1..98.

Crossrefs

Cf. A051990, A051991, A051992, A051994, A051995, A051996, A051997, A051998.

Sequence in context: A010263 A011303 A225405 * A174530 A280490 A350091

Adjacent sequences: A051990 A051991 A051992 * A051994 A051995 A051996

Keyword

nonn,fini,full

Author

N. J. A. Sloane, Jan 04 2000

Extensions

a(83) and following from Georg Fischer, Sep 21 2021

Status

approved