# Protected Cells in Compositions

Protected Cells in Compositions Compositions (ordered partitions) of n are finite sequences of positive integers that sum to n. We represent a composition of n as a bargraph with area n such that the height of the i-th column of the bargraph equals the size of the i-th part of the composition. We consider the concept of protected cells and protected columns in the bargraph representation of the composition. An r-protected cell is a cell in which the shortest path to the outside has at least r+1\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$r+1$$\end{document} steps (up, down, left or right). We obtain the average number of r-protected cells and protected columns. Finally we study the total protection number of a composition and compute the mean of this quantity over all compositions of n. We define the total protection number of a composition π\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\pi$$\end{document} to be the sum of the protection numbers of each individual cell in that composition. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Mathematics in Computer Science Springer Journals

# Protected Cells in Compositions

, Volume 16 (1) – Mar 1, 2022
8 pages

/lp/springer-journals/protected-cells-in-compositions-0n0AMkfGJL
Publisher
Springer Journals
Copyright © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2021
ISSN
1661-8270
eISSN
1661-8289
DOI
10.1007/s11786-021-00519-y
Publisher site
See Article on Publisher Site

### Abstract

Compositions (ordered partitions) of n are finite sequences of positive integers that sum to n. We represent a composition of n as a bargraph with area n such that the height of the i-th column of the bargraph equals the size of the i-th part of the composition. We consider the concept of protected cells and protected columns in the bargraph representation of the composition. An r-protected cell is a cell in which the shortest path to the outside has at least r+1\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$r+1$$\end{document} steps (up, down, left or right). We obtain the average number of r-protected cells and protected columns. Finally we study the total protection number of a composition and compute the mean of this quantity over all compositions of n. We define the total protection number of a composition π\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\pi$$\end{document} to be the sum of the protection numbers of each individual cell in that composition.

### Journal

Mathematics in Computer ScienceSpringer Journals

Published: Mar 1, 2022

Keywords: Compositions; Protected cells; Bargraphs; Generating functions; Primary 05A15; 05A16; Secondary

### References

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