A029704 Q(sqrt(n)) has class number 4.

82, 130, 145, 170, 195, 210, 219, 231, 255, 274, 290, 291, 322, 323, 330, 370, 390, 410, 434, 435, 438, 445, 455, 462, 483, 505, 510, 514, 530, 546, 555, 570, 579, 582, 595, 610, 615, 626, 627, 651, 658, 663, 674, 689, 690, 706, 714, 715, 723, 731, 754, 759, 770

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Index entries for sequences related to quadratic fields

Mathematica

Select[Range[770], SquareFreeQ[#] && NumberFieldClassNumber@Sqrt[#] == 4 &] (* Arkadiusz Wesolowski, Oct 18 2012 *)

Prog

(PARI) is(n)=if(issquarefree(n), my(c=bnfinit('x^2-n).cyc); c==[4] || c==[2, 2], 0) \\ Charles R Greathouse IV, Oct 18 2012

Crossrefs

Cf. A003172, A029702-A029703, A029705, A218038-A218042.

Sequence in context: A037159 A223088 A039547 * A260835 A173087 A264352

Adjacent sequences: A029701 A029702 A029703 * A029705 A029706 A029707

Keyword

nonn

Author

Paolo Dominici (pl.dm(AT)libero.it)

Extensions

Initial term added by Arkadiusz Wesolowski, Oct 18 2012

Status

approved