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A029704 Q(sqrt(n)) has class number 4. 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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 17 22:53 EDT 2019. Contains 327147 sequences. (Running on oeis4.)