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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. 0

%I

%S -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,

%T 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,

%U -11,3,-15,1,-1,-21,-33,15,3,-3,-5,5,-17,7,3,5,1,-5,7,3,-13

%N 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.

%C Excludes discriminants appearing in A051990.

%D R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4.

%Y Cf. A051990-A051998.

%K sign,fini

%O 0,4

%A _N. J. A. Sloane_, Jan 04 2000

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Last modified October 21 09:09 EDT 2020. Contains 337911 sequences. (Running on oeis4.)