MathDB

9.6

Part of 2023 All-Russian Olympiad Regional Round

Problems(1)

Easy but nice NT with lcm

Source: ARO Regional stage 2023 9.6=10.6=11.6

2/16/2023
Does there exist a positive integer mm, such that if SnS_n denotes the lcm of 1,2,…,n1,2, \ldots, n, then Sm+1=4SmS_{m+1}=4S_m?
number theoryleast common multipleRussia