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A357600 Largest number k such that C(-k) is the cyclic group of order n, where C(D) is the class group of the quadratic field with discriminant D; or 0 if no such k exists. 1
163, 427, 907, 1555, 2683, 3763, 5923, 5947, 10627, 13843, 15667, 17803, 20563, 30067, 34483, 31243, 37123, 48427, 38707, 58507, 61483, 85507, 90787, 111763, 93307, 103027, 103387, 126043, 166147, 134467, 133387, 164803, 222643, 189883, 210907, 217627, 158923, 289963, 253507 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Different from the largest absolute value of negative fundamental discriminant d for class number n (which is equal to A038552(n) for n <= 100) at indices 8, 48, 52, 64, 68, 96, ...
Conjecture: all terms are odd.
LINKS
EXAMPLE
Let h(D) denote the class number of the quadratic field with discriminant D.
n | Largest number k such | k' = largest number k | C(-k')
| that C(-k) = C_n | such that h(-k) = n |
----+-----------------------+-----------------------+----------
8 | 5947 | 6307 | C_2 X C_4
48 | 333547 | 335203 | C_2 X C_24
52 | 435163 | 439147 | C_2 X C_26
64 | 680947 | 693067 | C_2 X C_32
68 | 780187 | 819163 | C_2 X C_34
96 | 1681243 | 1684027 | C_2 X C_48
CROSSREFS
Sequence in context: A142427 A142237 A142283 * A038552 A127883 A054466
KEYWORD
nonn,hard
AUTHOR
Jianing Song, Oct 05 2022
STATUS
approved

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Last modified March 1 09:59 EST 2024. Contains 370432 sequences. (Running on oeis4.)