English

Hadamard Products and Tilings

Combinatorics 2011-07-21 v2

Abstract

Louis W. Shapiro gave a combinatorial proof of a bilinear generating function for Chebyshev polynomials equivalent to the formula 1/(1-ax-x^2) * 1/(1-bx-x^2) = (1-x^2)/(1-abx-(2+a^2+b^2)x^2 -abx^3+x^4), where * denotes the Hadamard product. In a similar way, by considering tilings of a 2 by n rectangle with 1 by 1 and 1 by 2 bricks in the top row, and 1 by 1 and 1 by n bricks in the bottom row, we find an explicit formula for the Hadamard product 1/(1-ax-x^2) * x^m/(1-bx-x^n).

Keywords

Cite

@article{arxiv.0903.0594,
  title  = {Hadamard Products and Tilings},
  author = {Jong Hyun Kim},
  journal= {arXiv preprint arXiv:0903.0594},
  year   = {2011}
}

Comments

11 pages

R2 v1 2026-06-21T12:17:56.623Z