Subsets of positive integers arranged in canonical order.

Terms

a(0) =1a(1) =12a(2) =2a(3) =123a(4) =13a(5) =23a(6) =3a(7) =1234a(8) =124a(9) =134a(10) =234a(11) =14a(12) =24a(13) =34a(14) =4a(15) =12345a(16) =1235a(17) =1245a(18) =1345a(19) =2345a(20) =125a(21) =135a(22) =145a(23) =235a(24) =245a(25) =345a(26) =15a(27) =25a(28) =35a(29) =45