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FormalConjectures.ErdosProblems.«686»

Erdős Problem 686 #

Reference: erdosproblems.com/686

theorem Erdos686.erdos_686 :
True N2, k2, ∃ (n : ), mn + k, N = (∏ iFinset.Icc 1 k, (m + i)) / (∏ iFinset.Icc 1 k, (n + i))

Can every integer $N≥2$ be written as $$N=\frac{\prod_{1\leq i\leq k}(m+i)}{\prod_{1\leq i\leq k}(n+i)}$$ for some $k≥2$ and $m≥n+k$?

theorem Erdos686.erdos_686.variants.square :
True N2, IsSquare Nk2, ∃ (n : ), mn + k, N = (∏ iFinset.Icc 1 k, (m + i)) / (∏ iFinset.Icc 1 k, (n + i))

Can every square $N≥2$ be written as $$N=\frac{\prod_{1\leq i\leq k}(m+i)}{\prod_{1\leq i\leq k}(n+i)}$$ for some $k≥2$ and $m≥n+k$?

theorem Erdos686.erdos_686.variants.four :
True k2, ∃ (n : ), mn + k, 4 = (∏ iFinset.Icc 1 k, (m + i)) / (∏ iFinset.Icc 1 k, (n + i))

Can $4$ be written as $$4=\frac{\prod_{1\leq i\leq k}(m+i)}{\prod_{1\leq i\leq k}(n+i)}$$ for some $k≥2$ and $m≥n+k$?

theorem Erdos686.erdos_686.variants.four_two :
¬∃ (n : ), mn + 2, 4 = (∏ iFinset.Icc 1 2, (m + i)) / (∏ iFinset.Icc 1 2, (n + i))

The number $4$ cannot be written as $$4=\frac{\prod_{1\leq i\leq 2}(m+i)}{\prod_{1\leq i\leq 2}(n+i)}$$ for $m≥n+2$!

theorem Erdos686.erdos_686.variants.four_three :
¬∃ (n : ), mn + 3, 4 = (∏ iFinset.Icc 1 3, (m + i)) / (∏ iFinset.Icc 1 3, (n + i))

The number $4$ cannot be written as $$4=\frac{\prod_{1\leq i\leq 2}(m+i)}{\prod_{1\leq i\leq 2}(n+i)}$$ for $m≥n+2$!

See comment section on erdosproblems.com

theorem Erdos686.erdos_686.variants.nine :
True k2, ∃ (n : ), mn + k, 9 = (∏ iFinset.Icc 1 k, (m + i)) / (∏ iFinset.Icc 1 k, (n + i))

Can $9$ be written as $$9=\frac{\prod_{1\leq i\leq k}(m+i)}{\prod_{1\leq i\leq k}(n+i)}$$ for some $k≥2$ and $m≥n+k$?

theorem Erdos686.erdos_686.variants.twenty_five :
True k2, ∃ (n : ), mn + k, 25 = (∏ iFinset.Icc 1 k, (m + i)) / (∏ iFinset.Icc 1 k, (n + i))

Can $25$ be written as $$25=\frac{\prod_{1\leq i\leq k}(m+i)}{\prod_{1\leq i\leq k}(n+i)}$$ for some $k≥2$ and $m≥n+k$?

theorem Erdos686.erdos_686.variants.non_square :
True N2, ¬IsSquare Nk2, ∃ (n : ), mn + k, N = (∏ iFinset.Icc 1 k, (m + i)) / (∏ iFinset.Icc 1 k, (n + i))

Can every non-square $N≥2$ be written as $$N=\frac{\prod_{1\leq i\leq k}(m+i)}{\prod_{1\leq i\leq k}(n+i)}$$ for some $k≥2$ and $m≥n+k$?