A351669 Discriminants of imaginary quadratic fields with class number 31 (negated).

719, 911, 2927, 3251, 3727, 3779, 4159, 4951, 5651, 6131, 6491, 7639, 8647, 9203, 10427, 11863, 12347, 12923, 13043, 13219, 13687, 14627, 14731, 15923, 17987, 18803, 19219, 20611, 24691, 24979, 28051, 32083, 32363, 35491, 38851, 39667, 39883, 41227, 41539

Offset: 1

Author

Andy Huchala, Mar 24 2022

Keywords

• nonn
• fini
• full

Comments

Sequence contains 73 terms; largest is 133387.

The class group of Q[sqrt(-d)] is isomorphic to C_31 for all d in this sequence.

Links

• Andy Huchala, Table of n, a(n) for n = 1..73
• 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] == 31]