Numbers k such that string '84' occurs in the base 10 representation of k but not of k-1.

Terms

a(0) =84a(1) =184a(2) =284a(3) =384a(4) =484a(5) =584a(6) =684a(7) =784a(8) =840a(9) =884a(10) =984a(11) =1084a(12) =1184a(13) =1284a(14) =1384a(15) =1484a(16) =1584a(17) =1684a(18) =1784a(19) =1840a(20) =1884a(21) =1984a(22) =2084a(23) =2184a(24) =2284a(25) =2384a(26) =2484a(27) =2584a(28) =2684a(29) =2784