A351668 Discriminants of imaginary quadratic fields with class number 30 (negated).

671, 815, 1007, 1844, 2036, 2071, 2191, 2264, 2319, 2599, 2708, 3188, 3223, 3284, 3439, 3991, 4087, 4276, 4696, 4835, 4859, 4979, 5579, 5912, 6107, 6459, 6463, 6488, 6535, 6635, 7087, 7115, 7303, 7576, 7835, 7971, 8259, 8267, 8367, 8483, 8948, 9019, 9076

Offset: 1

Author

Andy Huchala, Mar 24 2022

Keywords

• nonn
• fini
• full

Comments

Sequence contains 255 terms; largest is 134467.

The class group of Q[sqrt(-d)] is isomorphic to C_30 for all d in this sequence.

Links

• Andy Huchala, Table of n, a(n) for n = 1..255
• Eric Weisstein's World of Mathematics, Class Number

Crossrefs

Cf. A006203, A013658, A014602, A014603, A046002-A046020, A046125, A056987, A351664.

Programs

Sage

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)];
[-a[0] for a in ls if a[1] == 30]