|
|
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
|
Table of n, a(n) for n=1..76.
|
|
CROSSREFS
|
Cf. A051990, A051991, A051992, A051993, A051994, A051995, A051996, A051998.
Sequence in context: A155828 A226203 A327791 * A155744 A086869 A348953
Adjacent sequences: A051994 A051995 A051996 * A051998 A051999 A052000
|
|
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
|
|
|
|