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A046012
Discriminants of imaginary quadratic fields with class number 15 (negated).
5
239, 439, 751, 971, 1259, 1327, 1427, 1567, 1619, 2243, 2647, 2699, 2843, 3331, 3571, 3803, 4099, 4219, 5003, 5227, 5323, 5563, 5827, 5987, 6067, 6091, 6211, 6571, 7219, 7459, 7547, 8467, 8707, 8779, 9043, 9907, 10243, 10267, 10459, 10651
OFFSET
1,1
COMMENTS
68 discriminants in this sequence (proved).
LINKS
R. J. Mathar, Table of n, a(n) for n=1..68 (full sequence)
Steven Arno, M. L. Robinson, Ferrell S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330.
Duncan A. Buell, Small class numbers and extreme values of L-functions of quadratic fields, Math. Comp., 31 (1977), 786-796.
C. Wagner, Class Number 5, 6 and 7, Math. Comput. 65, 785-800, 1996.
Eric Weisstein's World of Mathematics, Class Number.
MATHEMATICA
Reap[ For[n = 1, n < 12000, n++, s = Sqrt[-n]; If[ NumberFieldClassNumber[s] == 15, d = -NumberFieldDiscriminant[s]; Print[d]; Sow[d]]]][[2, 1]] // Union (* Jean-François Alcover, Oct 05 2012 *)
KEYWORD
nonn,fini,full
STATUS
approved