%I M0210 #9 Jan 27 2014 08:57:35
%S 1,2,2,2,2,2,2,4,2,2,2,2,4,2,4,4,2,4,4,2,2,2,4,4,2,2,2,4,2,4,2,2,4,6,
%T 4,2,2,4,4,2,4,4,2,2,2,4,4,4,4,2,4,2,4,2,4,2,2,4,2,6,4,4,2,4,4,2,4,2,
%U 2,2,4,4,4,2,4,4,4,4,4,2,4,8,2,2,4,2,8,2,2,4,2,8,4,6,8,2,4,8,12,4,2,4,4,2
%N Class number of quadratic forms with discriminant 4n, n == 2,3^( mod 4).
%D D. A. Buell, Binary Quadratic Forms. Springer-Verlag, NY, 1989, pp. 224-241.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%Y Cf. A003647.
%K nonn
%O 2,2
%A _N. J. A. Sloane_, _Mira Bernstein_