Number of positive integers <= 2^n of form 5 x^2 + 9 y^2.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =3a(5) =5a(6) =10a(7) =18a(8) =32a(9) =60a(10) =110a(11) =207a(12) =391a(13) =739a(14) =1411a(15) =2695a(16) =5158a(17) =9941a(18) =19187a(19) =37151a(20) =72038a(21) =140000a(22) =272470a(23) =531133a(24) =1036727a(25) =2025812a(26) =3962913a(27) =7759632a(28) =15207510a(29) =29828260