a(n) = a(n-1) + a(n-2) + 1, with a(0) = 1 and a(1) = 11.

Terms

a(0) =1a(1) =11a(2) =13a(3) =25a(4) =39a(5) =65a(6) =105a(7) =171a(8) =277a(9) =449a(10) =727a(11) =1177a(12) =1905a(13) =3083a(14) =4989a(15) =8073a(16) =13063a(17) =21137a(18) =34201a(19) =55339a(20) =89541a(21) =144881a(22) =234423a(23) =379305a(24) =613729a(25) =993035a(26) =1606765a(27) =2599801a(28) =4206567a(29) =6806369