Concatenations x||1||x for numbers x.

Terms

a(0) =111a(1) =212a(2) =313a(3) =414a(4) =515a(5) =616a(6) =717a(7) =818a(8) =919a(9) =10110a(10) =11111a(11) =12112a(12) =13113a(13) =14114a(14) =15115a(15) =16116a(16) =17117a(17) =18118a(18) =19119a(19) =20120a(20) =21121a(21) =22122a(22) =23123a(23) =24124a(24) =25125a(25) =26126a(26) =27127a(27) =28128a(28) =29129a(29) =30130