Numbers k such that 3 and 5 occur juxtaposed in the base-10 representation of k but not of k-1.

Terms

a(0) =35a(1) =53a(2) =135a(3) =153a(4) =235a(5) =253a(6) =335a(7) =350a(8) =435a(9) =453a(10) =530a(11) =553a(12) =635a(13) =653a(14) =735a(15) =753a(16) =835a(17) =853a(18) =935a(19) =953a(20) =1035a(21) =1053a(22) =1135a(23) =1153a(24) =1235a(25) =1253a(26) =1335a(27) =1350a(28) =1435a(29) =1453