A351664 Discriminants of imaginary quadratic fields with class number 26 (negated).

551, 951, 1247, 1256, 1735, 1832, 2651, 2771, 2792, 2823, 2839, 2984, 3092, 3327, 3368, 3611, 3736, 3903, 3992, 4052, 4207, 4244, 4376, 4739, 5123, 5435, 5524, 5891, 6059, 6443, 6515, 6587, 6676, 6847, 6891, 6964, 7156, 8003, 8339, 8383, 8408, 8691, 8743

Offset: 1

Author

Andy Huchala, Feb 16 2022

Keywords

• nonn
• fini
• full

Comments

Sequence contains 190 terms; largest is 103027.

The class group of Q[sqrt(-d)] is isomorphic to C_26 for all d in this sequence.

Links

• Andy Huchala, Table of n, a(n) for n = 1..190
• Eric Weisstein's World of Mathematics, Class Number.

Crossrefs

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

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] == 26]