Fibonacci sequence beginning 2, 6.

Terms

a(0) =2a(1) =6a(2) =8a(3) =14a(4) =22a(5) =36a(6) =58a(7) =94a(8) =152a(9) =246a(10) =398a(11) =644a(12) =1042a(13) =1686a(14) =2728a(15) =4414a(16) =7142a(17) =11556a(18) =18698a(19) =30254a(20) =48952a(21) =79206a(22) =128158a(23) =207364a(24) =335522a(25) =542886a(26) =878408a(27) =1421294a(28) =2299702a(29) =3720996