In C. McMullen's [Uniformly Diophantine numbers in a fixed real quadratic field][1] generalized Fibonacci sequence are defined as follows: $f_0=0,f_1=1,f_m=tf_{m-1}-nf_{m-2}$ where some fixed $t\in \mathbb Z$ and $n$ is $+1$ or $-1$. For example, for $t=1,n=-1$ we get the usual Fibonacci sequence. My question: Does there exist $t,n$ such that the resulting Fibonacci sequence has infinitely primes in it? I think that it is conjectured to hold for the usual Fibonacci sequence. A weaker assertion: Does there exist $t,n$ such that the resulting Fibonacci has infinitely many elements with a large prime divisor, e.g., infinitely many $m$'s such that $p_m|f_m$, $p_m$ prime and $\frac{p_m}{f_m}>C$ for some C>0? A related paper (which does not contain any answer to the above questions) is (By Y. Bugeaud F. Luca, M. Mignotte et S. Siksek) [On Fibonacci numbers with few prime divisors][2]. I'll be happy to know about any reference that deal with these generalized sequences. [1]: http://www.math.harvard.edu/~ctm/papers/home/text/papers/cf/cf.pdf [2]: http://www-irma.u-strasbg.fr/~bugeaud/travaux/OmegaDef.pdf