Sharper bounds for zero-one matrices with prescribed margins

Refine the upper bound on the number of zero-one matrices with specified row and column margins by using the multivariate Kummer carry structure underlying Algorithm 1.

Background

A corollary of Section 5 of Bernard–Letac gives an upper bound for the number of zero-one matrices with prescribed margins. The paper observes that the carry information computed by the p-adic valuation algorithm may provide additional structure for improving this estimate.

The problem is connected with the longstanding counting challenge identified by Ryser and is explicitly left unresolved.

References

Refining this bound using the carry structure of Algorithm~\ref{alg:kummer} remains an open problem, which is related to the longstanding challenge identified by Ryser.

Algorithms, Complexity, and Entropy of the Bernard-Letac Fair-Sampling Construction  (2608.20234 - Gravel, 20 Aug 2026) in Open Problem P7, Section 5; mentioned after Algorithm 1