

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
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OFFSET

1,1


REFERENCES

H. Cohen, Advanced Topics in Computational Number Theory, Springer, 2000, p. 534.
H. Hasse, Number Theory, SpringerVerlag, 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 & ] (* JeanFrançois Alcover, Jul 04 2013 *)


CROSSREFS

Cf. A003656, A094619.
Sequence in context: A100333 A116309 A126816 * 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



