Positions of odd numbers in A000404 (sums of 2 nonzero squares).

Terms

a(0) =2a(1) =5a(2) =6a(3) =9a(4) =11a(5) =14a(6) =16a(7) =17a(8) =20a(9) =22a(10) =23a(11) =26a(12) =30a(13) =31a(14) =33a(15) =36a(16) =39a(17) =40a(18) =42a(19) =44a(20) =48a(21) =49a(22) =52a(23) =53a(24) =54a(25) =58a(26) =60a(27) =63a(28) =64a(29) =65