What is the smallest Skewes's number
Status Open · unsolvedmath.comLLM status Open unverified
Top Open Problems Not reported cataloguedOpenOpenStatement
Definitions and mathematical statement
Shared notation.
$\mathbb N=\{1,2,\ldots\}$, and $\mathbb Z,\mathbb Q,\mathbb R,\mathbb C$ denote the integers, rationals, reals and complex numbers. Any other conventions are specified locally.For a real $x\ge2$, let $\pi(x)=\#\{p\le x:p\text{ is a positive prime}\}$ and define the unshifted logarithmic integral by \[\operatorname{li}(x)=\lim_{\delta\downarrow0}\left(\int_0^{1-\delta}\frac{dt}{\log t}+\int_{1+\delta}^{x}\frac{dt}{\log t}\right).\] Thus $\operatorname{li}$ uses Cauchy principal value at $1$, rather than the offset integral starting at $2$. The least natural-number crossover is \[x_0=\min\{n\in\mathbb N:n\ge2,\ \pi(n)>\operatorname{li}(n)\}.\] Littlewood's sign-change theorem guarantees that the displayed set is nonempty.
Statement recorded in the supplied source.
What is the exact value of $x_0$, the smallest natural number at which $\pi(x)$ exceeds $\operatorname{li}(x)$? [S2]Short English statement
Determine the very first integer where the prime-counting function exceeds the unshifted logarithmic integral.Sources
- S1 ULAM.AI and the UnsolvedMath Contributors, UnsolvedMath: A Curated Collection of Open Mathematics Problems, record 9400170 (AMR-093-0170). CC BY 4.0. https://huggingface.co/datasets/ulamai/UnsolvedMath.
- S2 Wikipedia contributors, Skewes's number, revision 1370942184 (2026) Definition and evidence. https://en.wikipedia.org/w/index.php?title=Skewes%27s+number&oldid=1370942184.
- S3 Wikipedia contributors, Logarithmic integral function, revision 1339812367 (2026) Integral representation; Offset logarithmic integral. https://en.wikipedia.org/w/index.php?title=Logarithmic+integral+function&oldid=1339812367.
- S4 Wikipedia contributors, List of unsolved problems in mathematics, revision 1366636767 (2026) Number theory, What is the smallest Skewes's number. https://en.wikipedia.org/w/index.php?title=List_of_unsolved_problems_in_mathematics&oldid=1366636767#Number_theory.
Statement licence: CC-BY-4.0 · Source file
Contributions 0
No attempts yet. Significant partial results and substantial reductions are welcome. Contribute an attempt.