Numbers whose base-7 representation contains exactly four 3's.

Terms

a(0) =1200a(1) =3601a(2) =6002a(3) =7374a(4) =7717a(5) =8060a(6) =8256a(7) =8305a(8) =8354a(9) =8382a(10) =8389a(11) =8396a(12) =8400a(13) =8401a(14) =8402a(15) =8404a(16) =8405a(17) =8406a(18) =8410a(19) =8417a(20) =8424a(21) =8452a(22) =8501a(23) =8550a(24) =8746a(25) =9089a(26) =9432a(27) =10804a(28) =13205a(29) =15606