A054157 - OEIS

%I #11 Jan 24 2022 03:56:59

%S 0,1,1,3,5,10,17,33,58,109,202,379,720,1369,2618,5031,9701,18766,

%T 36387,70688,137572,268208,523581,1023425,2002829,3923400,7692930,

%U 15096706,29649082,58270386,114596178,225503077,443996993,874648723,1723849033

%N Number of positive integers <= 2^n of form 2 x^2 + 7 y^2.

%H <a href="/index/Qua#quadpop">Index entries for sequences related to populations of quadratic forms</a>

%Y Cf. A020675.

%K nonn

%O 0,4

%A _David W. Wilson_