a(n) = a(n-1) + a(n-2) + 1, with a(0) = 1 and a(1) = 10.

Terms

a(0) =1a(1) =10a(2) =12a(3) =23a(4) =36a(5) =60a(6) =97a(7) =158a(8) =256a(9) =415a(10) =672a(11) =1088a(12) =1761a(13) =2850a(14) =4612a(15) =7463a(16) =12076a(17) =19540a(18) =31617a(19) =51158a(20) =82776a(21) =133935a(22) =216712a(23) =350648a(24) =567361a(25) =918010a(26) =1485372a(27) =2403383a(28) =3888756a(29) =6292140