%I A035120
%S A035120 40,60,65,85,104,105,120,136,140,145,156,165,168,185,204,205,
%T A035120 220,221,229,232,257,264,265,273,280,285,296,305,312,316,321,
%U A035120 328,345,348,357,364,365,377,380,385,401,408,424,429,440,444,445,456,460,
               465,469,473
%N A035120 Discriminants of real quadratic number fields with class number >= 2.
%D A035120 H. Cohen, Advanced Topics in Computational Number Theory, Springer, 2000, 
               p. 534.
%D A035120 H. Hasse, Number Theory, Springer-Verlag, NY, 1980, p. 576.
%H A035120 T. D. Noe, <a href="b035120.txt">Table of n, a(n) for n=1..1000</a>
%H A035120 X.-F. Roblot and Igor Schein, <a href="http://euler.univ-lyon1.fr/home/
               roblot/tables.html#1">Hilbert class field of totally real fields 
               of degree 2, 3 and 4</a>.
%H A035120 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               ClassNumber.html">Class Number</a>
%t A035120 Needs["NumberTheory`NumberTheoryFunctions`"] (*then*) Flatten[Position[ClassNumber/
               @Range[600], 2, {1}]]
%Y A035120 Cf. A003656, A094619.
%Y A035120 Sequence in context: A100333 A116309 A126816 this_sequence A094619 A052475 
               A060672
%Y A035120 Adjacent sequences: A035117 A035118 A035119 this_sequence A035121 A035122 
               A035123
%K A035120 nonn,nice,easy
%O A035120 1,1
%A A035120 N. J. A. Sloane (njas(AT)research.att.com).
%E A035120 More terms from Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), 
               May 15 2002