Numbers whose set of base-7 digits is {1,4}.

Terms

a(0) =1a(1) =4a(2) =8a(3) =11a(4) =29a(5) =32a(6) =57a(7) =60a(8) =78a(9) =81a(10) =204a(11) =207a(12) =225a(13) =228a(14) =400a(15) =403a(16) =421a(17) =424a(18) =547a(19) =550a(20) =568a(21) =571a(22) =1429a(23) =1432a(24) =1450a(25) =1453a(26) =1576a(27) =1579a(28) =1597a(29) =1600