n appears 2n times, for n >= 1; also nearest integer to square root of n.

Terms

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