On non-repetitive sequences of arithmetic progressions:the cases $k\in \{4,5,6,7,8\}$

Borut Lužar, Martina Mockovčiaková, Pascal Ochem +2

A $d$-subsequence of a sequence $\phi =x_1\dots x_n$ 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 seque…