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Erdős Problems

1,217 source-owned questions · 604 with a formal statement · searchable by statement, number, topic and source status.

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  • Open per source608
  • Resolved per source556
  • Other source status53
Exact formal statement available604 / 1,217
With Repository-reviewed evidence2 / 1,217
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Problems

21 Problems

SelectNumberQuestionOpen
#18Erdős's Theorem. Erdős proved that h(n!)<nh(n!) < n for all n≥1n \ge 1.Source says openFormalized
#373Show that the equation n!=a_1!a_2!···a_k!, with n−1 > a_1 ≥ a_2 ≥ ··· ≥ a_k, has only finitely many solutions.Source says openFormalized
#390Does there exists a constant c such that f n - 2 * n ~ c * (n / log n)?Source says openFormalized
#391No statement retained — open to read what the source holdsSource says provedNo formal declaration
#392Let A(n)A(n) denote the least value of tt such that n!=a1⋯at n! = a_1 \cdots a_t with a1≤⋯≤at≤n2a_1 \leq \cdots \leq a_t\leq n^2. Then A(n)=n2−n2log⁡n+o(nlog⁡n). A(n) = \frac{n}{2} - \frac{n}{2\log n} + o\left(\frac{n}{\log n}\right). Source says proved (Lean)Formalized
#393No statement retained — open to read what the source holdsSource says openNo formal declaration
#398Brocard's Problem Does n!+1=m2n! + 1 = m^2 have integer solutions other than n=4,5,7n = 4, 5, 7?Source says falsifiableFormalized
#399Is it true that there are no solutions to n! = x^k ± y^k with x,y,n ∈ ℕ, x*y > 1, and k > 2?Source says disproved (Lean)Formalized
#400Can one show that ∑n≤xgk(n)∼ckxlog⁡x\sum_{n\leq x}g_k(n) \sim c_k x\log x for some constant ckc_k?Source says openFormalized
#401Is there some function f(r)f(r) such that f(r)→∞f(r)\to \infty as r→∞r\to\infty, such that, for infinitely many nn, there exist a1,a2a_1,a_2 with a1+a2>n+f(r)log⁡na_1+a_2> n+f(r)\log n such that a1!a2!∣n!2n3n⋯prna_1!a_2! \mid n!2^n3^n\cdots p_r^n?Source says proved (Lean)Formalized
#403Does the equation 2m=a1!+⋯+ak!2^m=a_1!+\cdots+a_k! with a1<a2<⋯<aka_1<a_2<\cdots <a_k have only finitely many solutions?Source says proved (Lean)Formalized
#404No statement retained — open to read what the source holdsSource says openNo formal declaration
#405No statement retained — open to read what the source holdsSource says provedNo formal declaration
#419If τ(n)\tau(n) counts the number of divisors of nn, then what is the set of limit points of τ((n+1)!)τ(n!)? \frac{\tau((n+1)!)}{\tau(n!)}? Source says solved (Lean)Formalized
#478No statement retained — open to read what the source holdsSource says openNo formal declaration
#646Let p1,…,pkp_1,\ldots,p_k be distinct primes. Are there infinitely many nn such that n!n! is divisible by an even power of each of the pip_i?Source says proved (Lean)Formalized
#727Let k≥2k ≥ 2. Does ((n+k)!)2∣(2n)!((n+k)!)^2∣(2n)! hold for infinitely many nn?Source says openFormalized
#728Let ε\varepsilon be sufficiently small and C,C′>0C, C' > 0. Are there integers a,b,na, b, n such that a,b>εna! b!∣n! (a+b−n)!,a, b > \varepsilon n\quad a!\, b! \mid n!\, (a + b - n)!, and Clog⁡n<a+b−n<C′log⁡n?C \log n < a + b - n < C' \log n ?Source says proved (Lean)Formalized
#729Let C>0C>0 be a constant. Are there infinitely many integers a,b,na,b,n with a+b>n+Clog⁡na+b> n+C\log n such that the denominator of n!a!b!\frac{n!}{a!b!}contains only primes ≪C1\ll_C 1?Source says proved (Lean)Formalized
#912Prove that there exists some c>0c>0 such that h(n)∼c(nlog⁡n)1/2h(n) \sim c \left(\frac{n}{\log n}\right)^{1/2} as n→∞n\to \infty.Source says openFormalized
#1108For each k≥2k \geq 2, does the set A={∑n∈Sn!:S⊂N finite}A = \left\{ \sum_{n\in S}n! : S\subset \mathbb{N}\text{ finite}\right\} of all finite sums of distinct factorials contain only finitely many kk-th powers?Source says openFormalized