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

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =13a(6) =25a(7) =43a(8) =83a(9) =157a(10) =296a(11) =564a(12) =1083a(13) =2077a(14) =4006a(15) =7733a(16) =14968a(17) =29044a(18) =56447a(19) =109864a(20) =214197a(21) =418080a(22) =816907a(23) =1598040a(24) =3129063a(25) =6132106a(26) =12027122a(27) =23606527a(28) =46366165a(29) =91127332