English

Counting scattered palindromes in a finite word

Discrete Mathematics 2021-08-06 v1

Abstract

We investigate the scattered palindromic subwords in a finite word. We start by characterizing the words with the least number of scattered palindromic subwords. Then, we give an upper bound for the total number of palindromic subwords in a word of length nn in terms of Fibonacci number FnF_n by proving that at most FnF_n new scattered palindromic subwords can be created on the concatenation of a letter to a word of length n1n-1. We propose a conjecture on the maximum number of scattered palindromic subwords in a word of length nn with qq distinct letters. We support the conjecture by showing its validity for words where qn2q\geq \frac{n}{2}.

Keywords

Cite

@article{arxiv.2108.02729,
  title  = {Counting scattered palindromes in a finite word},
  author = {Kalpana Mahalingam and Palak Pandoh},
  journal= {arXiv preprint arXiv:2108.02729},
  year   = {2021}
}