Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Claim. The answer to Problem 516 is yes. W. H. J. Fuchs, Proof of a conjecture of G. Pólya concerning gap series, Illinois J. Math. 7 (1963), no. 4, 661--667, doi:10.1215/ijm/1255645102, proves that if is an entire function of finite order with , then for every
holds for all outside a set of logarithmic density zero, where and are the maximum and minimum modulus of on $\lvert z\rvert=r$. Since the exceptional set has logarithmic density zero, radii with exist beyond every bound, and the trivial inequality gives the reverse bound, so
which is the question's statement, with the larger assertion about density as a bonus. The problem is Pólya's; the statement above follows the site's account of the paper; the proof is not reconstructed in this repository. Erdős's 1961 formulation, with the maximum term instead of the minimum modulus, is a different and much easier statement; the problem page records that reading.
Acceptance. Refereed: the paper appeared in the Illinois Journal of
Mathematics, a refereed journal; the publisher's record (Crossref) dates the
issue 1 December 1963, which is this page's date. Reviewed: the site's curator,
Thomas Bloom, labels the problem PROVED (LEAN) and credits this paper with the
affirmative solution on erdosproblems.com/516 (page last edited 28 December
2025), with the community database in agreement, which records the problem as
proved. A Lean development in Boris Alexeev's lean-proofs repository, linked
above at the revision of 15 September 2026 that the formal-conjectures statement
file points to, declares itself a formalization of a solution to the problem,
names Fuchs as its informal author, the Formal Conjectures authors as the
statement authors, and Codex and GPT-5.6 Sol as its formal authors, and builds
on Lean 4.33.0 with Mathlib; the community database records a Lean proof. That
development has not been built or audited in this repository, so it is a link
and not formalized evidence. No independent review is recorded here and none
is claimed.
Depends on. Nothing in this wiki: the argument is the paper's own.