a(n) is the concatenation of n and 8n.

Terms

a(0) =18a(1) =216a(2) =324a(3) =432a(4) =540a(5) =648a(6) =756a(7) =864a(8) =972a(9) =1080a(10) =1188a(11) =1296a(12) =13104a(13) =14112a(14) =15120a(15) =16128a(16) =17136a(17) =18144a(18) =19152a(19) =20160a(20) =21168a(21) =22176a(22) =23184a(23) =24192a(24) =25200a(25) =26208a(26) =27216a(27) =28224a(28) =29232a(29) =30240