%I #12 Sep 21 2021 15:47:19
%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(2), column k.
%Y Cf. A051990, A051991, A051992, A051993, A051994, A051995, A051996, A051998.
%K sign,fini,full
%O 1,4
%A _N. J. A. Sloane_, Jan 04 2000
%E Offset changed to 1 by _Georg Fischer_, Sep 21 2021
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