Skip to content / Đến nội dung
ThichHocToan.com

2011 AIME II Question 14

AIME · 2011 AIME II

Question 14

There are $N$ permutations $(a_1, a_2, \ldots, a_{30})$ of $1,$ $2,$ $\ldots,$ $30$ such that for $m \in \{2, 3, 5\},$ $m$ divides $a_{n+m} - a_n$ for all integers $n$ with $1 \le n \lt n + m \le 30.$ Find the remainder when $N$ is divided by $1000.$