%I A000205 M2350 N0928
%S A000205 1,1,3,4,8,14,25,45,82,151,282,531,1003,1907,3645,6993,13456,25978,50248,
%T A000205 97446,189291,368338,717804,1400699,2736534,5352182,10478044,20531668,
               40264582,
%U A000205 79022464,155196838,304997408,599752463,1180027022,2322950591,4575114295
%N A000205 Number of positive integers <= 2^n of form x^2 + 3 y^2.
%D A000205 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A000205 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A000205 P. Moree and H. J. J. te Riele, The hexagonal versus the square lattice, 
               Math. Comp. 73 (2004), no. 245, 451-473.
%D A000205 D. Shanks and L. P. Schmid, Variations on a theorem of Landau. Part I, 
               Math. Comp., 20 (1966), 551-569.
%H A000205 P. Moree and H. J. J. te Riele, <a href="http://arXiv.org/abs/math.NT/
               0204332">The hexagonal versus the square lattice</a>
%H A000205 <a href="Sindx_Qua.html#quadpop">Index entries for sequences related 
               to populations of quadratic forms</a>
%Y A000205 Cf. A000050.
%Y A000205 Sequence in context: A051788 A023623 A023558 this_sequence A136425 A005907 
               A049866
%Y A000205 Adjacent sequences: A000202 A000203 A000204 this_sequence A000206 A000207 
               A000208
%K A000205 nonn
%O A000205 0,3
%A A000205 N. J. A. Sloane (njas(AT)research.att.com).