Beginning with the natural numbers, swap [ k*sqrt(2) ] and [ k*(2 + sqrt(2)) ], for all k >= 1.

Terms

a(0) =3a(1) =6a(2) =1a(3) =10a(4) =13a(5) =2a(6) =17a(7) =20a(8) =23a(9) =4a(10) =27a(11) =30a(12) =5a(13) =34a(14) =37a(15) =40a(16) =7a(17) =44a(18) =47a(19) =8a(20) =51a(21) =54a(22) =9a(23) =58a(24) =61a(25) =64a(26) =11a(27) =68a(28) =71a(29) =12