Numbers with a single 3 in their base-5 expansion.

Terms

a(0) =3a(1) =8a(2) =13a(3) =15a(4) =16a(5) =17a(6) =19a(7) =23a(8) =28a(9) =33a(10) =38a(11) =40a(12) =41a(13) =42a(14) =44a(15) =48a(16) =53a(17) =58a(18) =63a(19) =65a(20) =66a(21) =67a(22) =69a(23) =73a(24) =75a(25) =76a(26) =77a(27) =79a(28) =80a(29) =81