cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A351677 Discriminants of imaginary quadratic fields with class number 39 (negated).

Original entry on oeis.org

1439, 2207, 2791, 3767, 3919, 4111, 5099, 5119, 6199, 6779, 9059, 9967, 10091, 10163, 10399, 10567, 10667, 11743, 12539, 13163, 13523, 14843, 14867, 15607, 16087, 16139, 16787, 17383, 18127, 21851, 23027, 24499, 26539, 27827, 30211, 30347, 30803, 32027, 32491
Offset: 1

Views

Author

Andy Huchala, Mar 27 2022

Keywords

Comments

Sequence contains 115 terms; largest is 253507.
The class group of Q[sqrt(-d)] is isomorphic to C_39 for all d in this sequence.

Crossrefs

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] == 39]