login
This site is supported by donations to The OEIS Foundation.

 

Logo

The submissions stack has been unacceptably high for several months now. Please voluntarily restrict your submissions and please help with the editing. (We don't want to have to impose further limits.)

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A035120 Discriminants of real quadratic number fields with class number >= 2. 7
40, 60, 65, 85, 104, 105, 120, 136, 140, 145, 156, 165, 168, 185, 204, 205, 220, 221, 229, 232, 257, 264, 265, 273, 280, 285, 296, 305, 312, 316, 321, 328, 345, 348, 357, 364, 365, 377, 380, 385, 401, 408, 424, 429, 440, 444, 445, 456, 460, 465, 469, 473 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

H. Cohen, Advanced Topics in Computational Number Theory, Springer, 2000, p. 534.

H. Hasse, Number Theory, Springer-Verlag, NY, 1980, p. 576.

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

X.-F. Roblot and Igor Schein, Hilbert class field of totally real fields of degree 2, 3 and 4.

Eric Weisstein's World of Mathematics, Class Number

MATHEMATICA

Select[Range[500], NumberFieldDiscriminant[Sqrt[#]] == # && NumberFieldClassNumber[Sqrt[#]] >= 2 & ] (* Jean-Fran├žois Alcover, Jul 04 2013 *)

CROSSREFS

Cf. A003656, A094619.

Sequence in context: A116309 A126816 A259061 * A094619 A052475 A182205

Adjacent sequences:  A035117 A035118 A035119 * A035121 A035122 A035123

KEYWORD

nonn,nice,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), May 15 2002

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified August 27 15:19 EDT 2015. Contains 261092 sequences.