a(n) = a(n-1) + a(n-2) + 1, with a(0) = 1 and a(1) = 7.

Terms

a(0) =1a(1) =7a(2) =9a(3) =17a(4) =27a(5) =45a(6) =73a(7) =119a(8) =193a(9) =313a(10) =507a(11) =821a(12) =1329a(13) =2151a(14) =3481a(15) =5633a(16) =9115a(17) =14749a(18) =23865a(19) =38615a(20) =62481a(21) =101097a(22) =163579a(23) =264677a(24) =428257a(25) =692935a(26) =1121193a(27) =1814129a(28) =2935323a(29) =4749453