Positive integers repeated.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =3a(5) =3a(6) =4a(7) =4a(8) =5a(9) =5a(10) =6a(11) =6a(12) =7a(13) =7a(14) =8a(15) =8a(16) =9a(17) =9a(18) =10a(19) =10a(20) =11a(21) =11a(22) =12a(23) =12a(24) =13a(25) =13a(26) =14a(27) =14a(28) =15a(29) =15