English

Products of binomial coefficients and unreduced Farey fractions

Number Theory 2016-08-11 v3

Abstract

This paper studies the product Gˉn\bar{G}_n of the binomial coefficients in the n-th row of Pascal's triangle, which equals the reciprocal of the product of all the reduced and unreduced Farey fractions of order n. It studies its size as a real number, measured by its logarithm log(Gˉn)log(\bar{G}_n), and its prime factorization, measured by the order of divisibility by a fixed prime p, each viewed as a function of n. It derives three formulas for its prime power divisibility, ordp(Gˉn)ord_p(\bar{G}_n), two of which relate it to base p radix expansions of n, and which display different facets of its behavior. These formulas are used to determine the maximal growth rate of each ordp(Gˉn)ord_p(\bar{G}_n) and structure of the fluctuations of these functions. It also defines analogous functions for all integer bases bb replacing prime bases. A final topic relates the factorizations of Gˉn\bar{G}_n to Chebyshev-type prime-counting estimates and the prime number theorem.

Keywords

Cite

@article{arxiv.1409.4145,
  title  = {Products of binomial coefficients and unreduced Farey fractions},
  author = {Jeffrey C. Lagarias and Harsh Mehta},
  journal= {arXiv preprint arXiv:1409.4145},
  year   = {2016}
}

Comments

30 pages, 3 figures, two Appendices. ; v2 is 31 pages, Appendices moved before reference list; v3 is 31 pages,corrections to match journal version