login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A218038 Numbers n such that Q(sqrt(n)) has class number 6. 11
235, 346, 427, 506, 574, 697, 785, 786, 842, 874, 894, 895, 898, 899, 906, 985, 1086, 1191, 1211, 1339, 1342, 1345, 1406, 1527, 1546, 1639, 1735, 1758, 1765, 1851, 1866, 1882, 1937, 1954, 2118, 2230, 2233, 2263, 2298, 2495, 2505, 2510, 2554, 2666, 2678, 2726 (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

Eric Weisstein's World of Mathematics, Class Number

MATHEMATICA

Select[Range[2726], SquareFreeQ[#] && NumberFieldClassNumber@Sqrt[#] == 6 &]

PROG

(PARI) is(n)=issquarefree(n) && qfbclassno(if(n%4>1, 4, 1)*n)==6 \\ Charles R Greathouse IV, Jan 19 2017

CROSSREFS

Cf. A003172, A029702-A029705, A218039-A218042.

Sequence in context: A036209 A077803 A049857 * A132903 A247474 A147148

Adjacent sequences:  A218035 A218036 A218037 * A218039 A218040 A218041

KEYWORD

nonn

AUTHOR

Arkadiusz Wesolowski, Oct 19 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 16 10:48 EDT 2021. Contains 343941 sequences. (Running on oeis4.)