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FormalConjectures.ErdosProblems.«730»

Erdős Problem 730 #

References:

Are there infinitely many pairs of integers $n < m$ such that $\binom{2n}{n}$ and $\binom{2m}{m}$ have the same set of prime divisors?

For example, $(87,88)$ and $(607,608)$ are such pairs.

theorem Erdos730.erdos_730.variants.two_div_forall (n : ) (h : 0 < n) :
2 (2 * n).choose n

Show that for all $n$, the binomial coefficient $\binom{2n}{n}$ is even.

theorem Erdos730.erdos_730.variants.delta_one (n m : ) (h : (n, m) S✝) :
m = n + 1

In every known example $(n, m) ∈ S$, we have $m = n + 1$.