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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 (list; graph; refs; listen; history; text; internal format)
 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. Keith Matthews, Tables of imaginary quadratic fields with small class numbers 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 *) CROSSREFS Cf. A006203, A013658, A014602, A014603, A046002-A046020. Sequence in context: A243102 A294092 A056086 * A152952 A142356 A142557 Adjacent sequences:  A046009 A046010 A046011 * A046013 A046014 A046015 KEYWORD nonn,fini,full AUTHOR STATUS approved

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Last modified June 7 05:20 EDT 2020. Contains 334837 sequences. (Running on oeis4.)