  Let $U = (U_n)_{n \geq 0}$ be a Lucas sequence and, for every prime number
$p$, let $\rho_U(p)$ be the rank of appearance of $p$ in $U$, that is, the
smallest positive integer $k$ such that $p$ divides $U_k$, whenever it exists.
Furthermore, let $d$ be an odd positive integer. Under some mild hypotheses, we
prove an asymptotic formula for the number of primes $p \leq x$ such that $d$
divides $\rho_U(p)$, as $x \to +\infty$.
