“…(If n = 3, then F (2, n) is a finite group.) As special cases of Theorem 3.1 and Corollary 3.2, one can obtain the results on the non-hyperbolicity of certain groups of Fibonacci type proved in [1,6,15]. As a further result, we have The following arises in a natural way from the above results: = (a, b, r, s), m, k and h for which G ε n (m, k, h) is the fundamental group of closed connected orientable 3-manifolds for infinitely many n. Then classify the topological and geometric structures of such manifolds.…”