  A $d$-subsequence of a sequence $\varphi = x_1\dots x_n$ is a subsequence
$x_i x_{i+d} x_{i+2d} \dots$, for any positive integer $d$ and any $i$, $1 \le
i \le n$. A \textit{$k$-Thue sequence} is a sequence in which every
$d$-subsequence, for $1 \le d \le k$, is non-repetitive, i.e. it contains no
consecutive equal subsequences. In 2002, Grytczuk proposed a conjecture that
for any $k$, $k+2$ symbols are enough to construct a $k$-Thue sequences of
arbitrary lengths. So far, the conjecture has been confirmed for $k \in
\{1,2,3,5\}$. Here, we present two different proving techniques, and confirm it
for all $k$, with $2 \le k \le 8$.
