Given a number $x \geq 3$, let $b(x) \in \{0,1\}$ be the second most significant digit (bit) of its binary representation, and $t(x)\in \{1,2\}$ the most significant digit of its ternary representation. In other words: $x = 2^n + b(x) 2^{n-1} + ... = t(x) 3^m + ...$ for some $n,m \geq 1$ Let $A$ be the set of $K \geq 0$ such that there exist integers $x \geq 3, y \geq 1$ and $$b(x + i y) + t(x + i y) = 1 \text{ for all } 0 \leq i \leq K$$ Informally the longest (integer) arithmetic progression that can be formed with numbers having $0$ as the second most significant digit of its binary representation and $1$ as the most significant digit of its ternary representation. <blockquote> Is $A$ finite?<br> Do exist $x,y$ such that $b(x + i y) + t(x + i y) = 1 \text{ for all } i$? </blockquote>