A054233 - OEIS

%I #5 Mar 30 2012 18:35:40

%S 1,1,2,2,4,9,14,26,47,85,158,295,552,1048,2000,3829,7373,14216,27505,

%T 53378,103728,201981,393900,769192,1503947,2943906,5767973,11311511,

%U 22200845,43605974,85707102,168564864,331720141,653151962,1286702079

%N Number of positive integers <= 2^n of form x^2 + 20 y^2.

%K nonn

%O 0,3

%A _David W. Wilson_