Accept one, reject one, accept two, reject two, ...

Terms

a(0) =1a(1) =3a(2) =4a(3) =7a(4) =8a(5) =9a(6) =13a(7) =14a(8) =15a(9) =16a(10) =21a(11) =22a(12) =23a(13) =24a(14) =25a(15) =31a(16) =32a(17) =33a(18) =34a(19) =35a(20) =36a(21) =43a(22) =44a(23) =45a(24) =46a(25) =47a(26) =48a(27) =49a(28) =57a(29) =58