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%I #10 Mar 27 2022 22:54:41
%S 671,815,1007,1844,2036,2071,2191,2264,2319,2599,2708,3188,3223,3284,
%T 3439,3991,4087,4276,4696,4835,4859,4979,5579,5912,6107,6459,6463,
%U 6488,6535,6635,7087,7115,7303,7576,7835,7971,8259,8267,8367,8483,8948,9019,9076
%N Discriminants of imaginary quadratic fields with class number 30 (negated).
%C Sequence contains 255 terms; largest is 134467.
%C The class group of Q[sqrt(-d)] is isomorphic to C_30 for all d in this sequence.
%H Andy Huchala, <a href="/A351668/b351668.txt">Table of n, a(n) for n = 1..255</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ClassNumber.html">Class Number</a>
%o (Sage)
%o ls = [(QuadraticField(-n, 'a').discriminant(), QuadraticField(-n, 'a').class_number()) for n in (0..10000) if is_fundamental_discriminant(-n) and not is_square(n)];
%o [-a[0] for a in ls if a[1] == 30]
%Y Cf. A006203, A013658, A014602, A014603, A046002-A046020, A046125, A056987, A351664.
%K nonn,fini,full
%O 1,1
%A _Andy Huchala_, Mar 24 2022