a(n) = a(n-1) + a(n-2) + 1 for n > 1, a(0)=1, a(1)=5.

Terms

a(0) =1a(1) =5a(2) =7a(3) =13a(4) =21a(5) =35a(6) =57a(7) =93a(8) =151a(9) =245a(10) =397a(11) =643a(12) =1041a(13) =1685a(14) =2727a(15) =4413a(16) =7141a(17) =11555a(18) =18697a(19) =30253a(20) =48951a(21) =79205a(22) =128157a(23) =207363a(24) =335521a(25) =542885a(26) =878407a(27) =1421293a(28) =2299701a(29) =3720995