Erdős problem 418 · problems.science

Are there infinitely many integers not of the form $n - \phi(n)$ ?

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5 retained statements2415f78e850a

FormalConjectures/ErdosProblems/

418.lean

Retained formal statement5 of 5

A solution to erdos_418 was shown by Browkin and Schinzel [BrSc95] by showing that any integer of the form $2^(k + 1)\cdot 509203$ is not of the form $n - \phi(n)$ .

FormalConjectures/ErdosProblems/418.leanErdos418.erdos_418.variants.soln1 lineExact file

1{x | ∃ k, 2 ^ (k + 1) * 509203 = x} ⊆ {x | ∃ n, n - n.totient = x}ᶜ

SolvedStatement only, no proof

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