Concatenations of cyclic permutations of initial positive integers.

Terms

a(0) =1a(1) =12a(2) =21a(3) =123a(4) =231a(5) =312a(6) =1234a(7) =2341a(8) =3412a(9) =4123a(10) =12345a(11) =23451a(12) =34512a(13) =45123a(14) =51234a(15) =123456a(16) =234561a(17) =345612a(18) =456123a(19) =561234a(20) =612345a(21) =1234567a(22) =2345671a(23) =3456712a(24) =4567123a(25) =5671234a(26) =6712345a(27) =7123456