Position of n in A026218.

Terms

a(0) =1a(1) =2a(2) =5a(3) =3a(4) =9a(5) =4a(6) =13a(7) =6a(8) =17a(9) =7a(10) =21a(11) =8a(12) =25a(13) =10a(14) =29a(15) =11a(16) =33a(17) =12a(18) =37a(19) =14a(20) =41a(21) =15a(22) =45a(23) =16a(24) =49a(25) =18a(26) =53a(27) =19a(28) =57a(29) =20