A Beatty sequence: a(n) = floor(n*(2 + sqrt(2))).

Terms

a(0) =3a(1) =6a(2) =10a(3) =13a(4) =17a(5) =20a(6) =23a(7) =27a(8) =30a(9) =34a(10) =37a(11) =40a(12) =44a(13) =47a(14) =51a(15) =54a(16) =58a(17) =61a(18) =64a(19) =68a(20) =71a(21) =75a(22) =78a(23) =81a(24) =85a(25) =88a(26) =92a(27) =95a(28) =99a(29) =102