%I A000286 M3251 N1312
%S A000286 0,1,1,4,5,11,20,36,65,119,218,412,770,1466,2784,5322,10226,19691,38048,
%T A000286 73665,142927,277822,540851,1054502,2058507,4023164,7871226,15414517,30213010,
%U A000286 59266164,116343183,228545303,449240025,883569304,1738768584,3423466797,
               6743729031
%N A000286 Number of positive integers <= 2^n of form 2 x^2 + 5 y^2.
%D A000286 D. Shanks and L. P. Schmid, Variations on a theorem of Landau. Part I, 
               Math. Comp., 20 (1966), 551-569.
%D A000286 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A000286 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%H A000286 <a href="Sindx_Qua.html#quadpop">Index entries for sequences related 
               to populations of quadratic forms</a>
%Y A000286 Sequence in context: A118143 A001350 A077238 this_sequence A036539 A000769 
               A050831
%Y A000286 Adjacent sequences: A000283 A000284 A000285 this_sequence A000287 A000288 
               A000289
%K A000286 nonn
%O A000286 0,4
%A A000286 N. J. A. Sloane (njas(AT)research.att.com).