English

Maximizing a combinatorial expression arising from crowd estimation

Combinatorics 2009-11-02 v1

Abstract

We determine, within 1, the value of N for which sum (s1 choose i)(s2 choose N)(s1 choose N-i)(N choose i) achieves its maximum value. Here s1 and s2 are fixed integers. This problem arises in studying the most likely value for the size of the union of A, B, and C if A and C are disjoint sets of size s1, and B is a set of size s2. Attempting to remove the 1 unit of indeterminacy leads to interesting conjectures about a family of rational functions.

Keywords

Cite

@article{arxiv.0910.5725,
  title  = {Maximizing a combinatorial expression arising from crowd estimation},
  author = {Donald M. Davis},
  journal= {arXiv preprint arXiv:0910.5725},
  year   = {2009}
}

Comments

21 pages

R2 v1 2026-06-21T14:05:04.967Z