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FormalConjectures.ErdosProblems.«677»

Erdős Problem 677 #

Reference: erdosproblems.com/677

Erdős expected very few solutions for $M(n, k) = M(m, l)$, where $m \geq n + k$ and $l > 1$. The only solutions he knew were the following.

theorem Erdos677.erdos_677 (m n k : ) :
k > 0m n + kFinset.lcmInterval m k Finset.lcmInterval n k

Denote by $M(n, k)$ the least common multiple of the finite set $\{n+1, \dotsc, n+k\}$. Is it true that for all $m \geq n + k$, we get $M(m, k) \neq M(n, k)$?