A351680 Discriminants of imaginary quadratic fields with class number 42 (negated).

1959, 2183, 2911, 3039, 3176, 3687, 3831, 4039, 4103, 4184, 4735, 4904, 4952, 5288, 5935, 5959, 6179, 6452, 6487, 6611, 6623, 6632, 6836, 7447, 7604, 7811, 7892, 7988, 8459, 8552, 8579, 8744, 8852, 9368, 9428, 9607, 10231, 10643, 10772, 10996, 11023, 11099

Offset

1,1

Comments

Sequence contains 339 terms; largest is 280267.

The class group of Q[sqrt(-d)] is isomorphic to C_42 for all d in this sequence.

Links

Andy Huchala, Table of n, a(n) for n = 1..339

Mark Watkins, Class numbers of imaginary quadratic fields, Mathematics of Computation, 73, pp. 907-938.

Eric Weisstein's World of Mathematics, Class Number

Prog

(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] == 42]

Crossrefs

Cf. A006203, A013658, A014602, A014603, A046002-A046020, A046125, A056987, A351664-A351679.

Sequence in context: A232389 A209946 A200857 * A157627 A072598 A159213

Adjacent sequences: A351677 A351678 A351679 * A351681 A351682 A351683

Keyword

nonn,fini,full

Author

Andy Huchala, Mar 28 2022

Status

approved