a(n) = j if n = [ j*sqrt(2) ], else a(n) = k if n = [ k*(2 + sqrt(2)) ].

Terms

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