Fibonacci[ (p - 1) ], where p = Prime[n].

Terms

a(0) =1a(1) =1a(2) =3a(3) =8a(4) =55a(5) =144a(6) =987a(7) =2584a(8) =17711a(9) =317811a(10) =832040a(11) =14930352a(12) =102334155a(13) =267914296a(14) =1836311903a(15) =32951280099a(16) =591286729879