A046004 Discriminants of imaginary quadratic fields with class number 7 (negated).

71, 151, 223, 251, 463, 467, 487, 587, 811, 827, 859, 1163, 1171, 1483, 1523, 1627, 1787, 1987, 2011, 2083, 2179, 2251, 2467, 2707, 3019, 3067, 3187, 3907, 4603, 5107, 5923

Offset

1,1

Links

Table of n, a(n) for n=1..31.

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.

Index entries for sequences related to quadratic fields

Mathematica

Union[(-NumberFieldDiscriminant[Sqrt[-#]] &) /@ Select[Range[6000], NumberFieldClassNumber[Sqrt[-#]] == 7 &]] (* Jean-François Alcover, Jun 27 2012 *)

Prog

(PARI) ok(n)={isfundamental(-n) && quadclassunit(-n).no == 7};
for(n=1, 6000, if(ok(n)==1, print1(n, ", "))) \\ G. C. Greubel, Mar 01 2019
(Sage) [n for n in (1..6000) if is_fundamental_discriminant(-n) and QuadraticField(-n, 'a').class_number()==7] # G. C. Greubel, Mar 01 2019

Crossrefs

Cf. A006203, A013658, A014602, A014603, A046002-A046020.

Cf. A191410.

Sequence in context: A157921 A033224 A142178 * A044322 A044703 A372188

Adjacent sequences: A046001 A046002 A046003 * A046005 A046006 A046007

Keyword

nonn,fini,full

Author

Eric W. Weisstein

Status

approved