English

About Some Relatives of Palindromes

Number Theory 2019-08-05 v1

Abstract

We introduce two new classes of integers. The first class consists of numbers NN for which there exists at least one nonnegative integer AA, such that the sum of AA and the sum of digits of NN, added to the reversal of the sum, gives NN. The second class consists of numbers NN for which there exists at least one nonnegative integer AA, such that the sum of AA and the sum of the digits of NN, multiplied by the reversal of the sum, gives NN. All palindromes that either have an even number of digits or an odd number of digits and the middle digit even belong to the first class, and all squares of palindromes with at least two digits belong to the second class. These classes contain and are strictly larger than the classes of bb-ARH numbers, respectively bb-MRH numbers introduced in Ni\c tic\u a \cite{N1}.

Keywords

Cite

@article{arxiv.1908.00713,
  title  = {About Some Relatives of Palindromes},
  author = {Viorel Nitica and Andrei Török},
  journal= {arXiv preprint arXiv:1908.00713},
  year   = {2019}
}
R2 v1 2026-06-23T10:37:56.970Z