  Let $\mathrm{TC}_r(X)$ denote the $r$-th topological complexity of a space
$X$. In many cases, the generating function $\sum_{r\ge
1}\mathrm{TC}_{r+1}(X)x^r$ is a rational function $\frac{P(x)}{(1-x)^2}$ where
$P(x)$ is a polynomial with $P(1)=\mathrm{cat}(X)$, that is, the asymptotic
growth of $\mathrm{TC}_r(X)$ with respect to $r$ is $\mathrm{cat}(X)$. In this
paper, we introduce a lower bound $\mathrm{MTC}_r(X)$ of $\mathrm{TC}_r(X)$ for
a rational space $X$, and estimate the growth of $\mathrm{MTC}_r(X)$.
