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

Terms

a(0) =0a(1) =2a(2) =5a(3) =7a(4) =10a(5) =13a(6) =15a(7) =18a(8) =21a(9) =23a(10) =26a(11) =29a(12) =31a(13) =34a(14) =37a(15) =39a(16) =42a(17) =45a(18) =47a(19) =50a(20) =53a(21) =55a(22) =58a(23) =61a(24) =63a(25) =66a(26) =69a(27) =71a(28) =74a(29) =77