Digits of n and of n-1 interleaved in decimal representation.

Terms

a(0) =10a(1) =21a(2) =32a(3) =43a(4) =54a(5) =65a(6) =76a(7) =87a(8) =98a(9) =190a(10) =1110a(11) =1121a(12) =1132a(13) =1143a(14) =1154a(15) =1165a(16) =1176a(17) =1187a(18) =1198a(19) =2109a(20) =2210a(21) =2221a(22) =2232a(23) =2243a(24) =2254a(25) =2265a(26) =2276a(27) =2287a(28) =2298a(29) =3209