Numbers k such that 6 and 8 occur juxtaposed in the base-10 representation of k but not of k-1.

Terms

a(0) =68a(1) =86a(2) =168a(3) =186a(4) =268a(5) =286a(6) =368a(7) =386a(8) =468a(9) =486a(10) =568a(11) =586a(12) =668a(13) =680a(14) =768a(15) =786a(16) =860a(17) =886a(18) =968a(19) =986a(20) =1068a(21) =1086a(22) =1168a(23) =1186a(24) =1268a(25) =1286a(26) =1368a(27) =1386a(28) =1468a(29) =1486