a(n) = Fibonacci(n) - 5.

Terms

a(0) =0a(1) =3a(2) =8a(3) =16a(4) =29a(5) =50a(6) =84a(7) =139a(8) =228a(9) =372a(10) =605a(11) =982a(12) =1592a(13) =2579a(14) =4176a(15) =6760a(16) =10941a(17) =17706a(18) =28652a(19) =46363a(20) =75020a(21) =121388a(22) =196413a(23) =317806a(24) =514224a(25) =832035a(26) =1346264a(27) =2178304a(28) =3524573a(29) =5702882