Ramanujan's prime-counting inequality holds for all x ≥ 38,358,837,683

Ramanujan observed that π(x)² < (ex/log x)·π(x/e) for all sufficiently large x. Dudek and Platt showed, assuming the Riemann hypothesis, that the last counterexample is x = 38,358,837,682. Unconditionally the inequality was known for 38,358,837,683 ≤ x ≤ e^103 (Johnston) and for x ≥ e^3158.442 (Axler). We close the gap: the inequality holds unconditionally for every x ≥ 38,358,837,683. The proof uses no verification of the Riemann hypothesis beyond the height 3·10¹² established by Platt and Trudgian. It combines a smoothed explicit formula of Büthe's type with three new explicit inputs: a log-free zero-density estimate near the 1-line, obtained by reworking Bellotti's argument with a sharp asymptotic evaluation of the Barban–Vehov mean square; a height-dependent zero-free region, obtained by evaluating the inequality of Bellotti, Trudgian and Yang exactly; and a repulsion lemma showing that two hypothetical zeros close to the 1-line cannot lie close to each other in height. All constants and auxiliary bounds are certified in rigorous interval (ball) arithmetic; the final scan over 57 ≤ log x < 3159 is run in double precision, with an explicit rounding analysis. Along the way we record several corrections to the explicit inputs we use, none of which affects the published main results. AI involvement: this work was carried out with substantial assistance from Claude (Anthropic), which performed most derivations, wrote and ran the certification code, and drafted the manuscript under the author's direction. Code, certificates and logs are included.

Authors

Institutions

Publication Details

Journal
Zenodo (CERN European Organization for Nuclear Research)
Published
2026-10-15
DOI
https://doi.org/10.5281/zenodo.23408097
Primary Topic
Analytic Number Theory Research
Type
preprint
Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
preprint

Ramanujan's prime-counting inequality holds for all x ≥ 38,358,837,683

Jaideep Sai Padhi
Zenodo (CERN European Organization for Nuclear Research)
Analytic Number Theory Research
preprint

Ramanujan's prime-counting inequality holds for all x ≥ 38,358,837,683

Jaideep Sai Padhi
preprint en

Abstract

Ramanujan observed that π(x)² < (ex/log x)·π(x/e) for all sufficiently large x. Dudek and Platt showed, assuming the Riemann hypothesis, that the last counterexample is x = 38,358,837,682. Unconditionally the inequality was known for 38,358,837,683 ≤ x ≤ e^103 (Johnston) and for x ≥ e^3158.442 (Axler). We close the gap: the inequality holds unconditionally for every x ≥ 38,358,837,683. The proof uses no verification of the Riemann hypothesis beyond the height 3·10¹² established by Platt and Trudgian. It combines a smoothed explicit formula of Büthe's type with three new explicit inputs: a log-free zero-density estimate near the 1-line, obtained by reworking Bellotti's argument with a sharp asymptotic evaluation of the Barban–Vehov mean square; a height-dependent zero-free region, obtained by evaluating the inequality of Bellotti, Trudgian and Yang exactly; and a repulsion lemma showing that two hypothetical zeros close to the 1-line cannot lie close to each other in height. All constants and auxiliary bounds are certified in rigorous interval (ball) arithmetic; the final scan over 57 ≤ log x < 3159 is run in double precision, with an explicit rounding analysis. Along the way we record several corrections to the explicit inputs we use, none of which affects the published main results. AI involvement: this work was carried out with substantial assistance from Claude (Anthropic), which performed most derivations, wrote and ran the certification code, and drafted the manuscript under the author's direction. Code, certificates and logs are included.

Zenodo (CERN European Organization for Nuclear Research)
Purdue University West Lafayette (US)
Analytic Number Theory Research
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.