a(n) = Fibonacci(n) + 2.

Terms

a(0) =2a(1) =3a(2) =3a(3) =4a(4) =5a(5) =7a(6) =10a(7) =15a(8) =23a(9) =36a(10) =57a(11) =91a(12) =146a(13) =235a(14) =379a(15) =612a(16) =989a(17) =1599a(18) =2586a(19) =4183a(20) =6767a(21) =10948a(22) =17713a(23) =28659a(24) =46370a(25) =75027a(26) =121395a(27) =196420a(28) =317813a(29) =514231