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A351680 Discriminants of imaginary quadratic fields with class number 42 (negated). 0
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 (list; graph; refs; listen; history; text; internal format)
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

Table of n, a(n) for n=1..42.

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-A351666.

Sequence in context: A232389 A209946 A200857 * A157627 A072598 A159213

Adjacent sequences:  A351677 A351678 A351679 * A351681 A351682 A351683

KEYWORD

nonn,fini

AUTHOR

Andy Huchala, Mar 28 2022

STATUS

approved

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Last modified August 7 22:13 EDT 2022. Contains 355995 sequences. (Running on oeis4.)