A046002 - OEIS

A046002

Discriminants of imaginary quadratic fields with class number 5 (negated).

47, 79, 103, 127, 131, 179, 227, 347, 443, 523, 571, 619, 683, 691, 739, 787, 947, 1051, 1123, 1723, 1747, 1867, 2203, 2347, 2683

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..25.

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[2700], NumberFieldClassNumber[Sqrt[-#]] == 5 &]] (* Jean-François Alcover, Jun 27 2012 *)

PROG

(PARI) select(n->qfbclassno(-n)==5, vector(670, n, 4*n+3)) \\ Charles R Greathouse IV, Apr 25 2013

(Sage) [n for n in (1..3000) if is_fundamental_discriminant(-n) and QuadraticField(-n, 'a').class_number()==5] # G. C. Greubel, Mar 01 2019

CROSSREFS

Cf. A006203, A013658, A014602, A014603, A046003-A046020.

Cf. A191410.

Sequence in context: A044028 A126095 A132259 * A347695 A132257 A240583

Adjacent sequences: A045999 A046000 A046001 * A046003 A046004 A046005

KEYWORD

nonn,fini,full

AUTHOR

Eric W. Weisstein

STATUS

approved