Position of n^2 + (n+1)^2 in A000404 (sums of 2 nonzero squares).

Terms

a(0) =2a(1) =5a(2) =9a(3) =16a(4) =22a(5) =30a(6) =40a(7) =49a(8) =63a(9) =74a(10) =89a(11) =104a(12) =120a(13) =138a(14) =155a(15) =174a(16) =195a(17) =217a(18) =238a(19) =262a(20) =287a(21) =312a(22) =339a(23) =366a(24) =396a(25) =425a(26) =453a(27) =489a(28) =520a(29) =553