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

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =10a(5) =18a(6) =33a(7) =60a(8) =111a(9) =205a(10) =385a(11) =725a(12) =1374a(13) =2610a(14) =4993a(15) =9578a(16) =18426a(17) =35568a(18) =68806a(19) =133411a(20) =259145a(21) =504222a(22) =982538a(23) =1917190a(24) =3745385a(25) =7324822a(26) =14339072a(27) =28095711a(28) =55095559a(29) =108124461