A054229 - OEIS

%I #8 Jan 25 2022 21:49:28

%S 1,1,2,2,5,9,16,27,52,91,173,322,606,1152,2191,4191,8060,15540,30018,

%T 58161,112891,219479,427440,833615,1627752,3182068,6226916,12196740,

%U 23910690,46911434,92104753,180957883,355748937,699779680,1377255678

%N Number of positive integers <= 2^n of form x^2 + 15 y^2.

%Y Cf. A243173.

%K nonn

%O 0,3

%A _David W. Wilson_