Octanacci numbers.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =8a(9) =15a(10) =29a(11) =57a(12) =113a(13) =225a(14) =449a(15) =897a(16) =1793a(17) =3578a(18) =7141a(19) =14253a(20) =28449a(21) =56785a(22) =113345a(23) =226241a(24) =451585a(25) =901377a(26) =1799176a(27) =3591211a(28) =7168169a(29) =14307889