%I M3251 N1312 #18 Oct 17 2017 05:52:26
%S 0,1,1,4,5,11,20,36,65,119,218,412,770,1466,2784,5322,10226,19691,
%T 38048,73665,142927,277822,540851,1054502,2058507,4023164,7871226,
%U 15414517,30213010,59266164,116343183,228545303,449240025,883569304,1738768584,3423466797,6743729031
%N Number of positive integers <= 2^n of form 2 x^2 + 5 y^2.
%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H D. Shanks and L. P. Schmid, <a href="http://dx.doi.org/10.1090/S0025-5718-1966-0210678-1">Variations on a theorem of Landau. Part I</a>, Math. Comp., 20 (1966), 551-569.
%H <a href="/index/Qua#quadpop">Index entries for sequences related to populations of quadratic forms</a>
%K nonn
%O 0,4
%A _N. J. A. Sloane_