Numbers whose set of base-7 digits is {3,4}.

Terms

a(0) =3a(1) =4a(2) =24a(3) =25a(4) =31a(5) =32a(6) =171a(7) =172a(8) =178a(9) =179a(10) =220a(11) =221a(12) =227a(13) =228a(14) =1200a(15) =1201a(16) =1207a(17) =1208a(18) =1249a(19) =1250a(20) =1256a(21) =1257a(22) =1543a(23) =1544a(24) =1550a(25) =1551a(26) =1592a(27) =1593a(28) =1599a(29) =1600