<?xml version="1.0" encoding="UTF-8"?>
<article article-type="Research Article">
  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher">journal-of-interdisciplinary-mathematics</journal-id>
      <journal-title-group>
        <journal-title>Journal of Interdisciplinary Mathematics</journal-title>
      </journal-title-group>
      <issn publication-format="electronic">2169-012X</issn>
      <issn publication-format="print">0972-0502</issn>
      <publisher>
        <publisher-name>Taru Publications</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.47974/JIM-2148</article-id>
      <title-group>
        <article-title>Telephone numbers extensions</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author" corresp="yes">
          <name>
            <surname>Fonseca</surname>
            <given-names>Carlos M. Da</given-names>
          </name>
          <aff>Department of Mathematics, Kuwait College of Science and Technology, Doha District, Safat, 13133, Kuwait</aff>
          <aff>Faculty of Applied Mathematics and Informatics, Kliment Ohridski Blvd. 8, Technical University of Sofia, Sofia, Bulgaria, 1000</aff>
          <aff>Chair of Computational Mathematics, University of Deusto, Bilbao, 48007, Bilbao</aff>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Shannon</surname>
            <given-names>Anthony G.</given-names>
          </name>
          <aff>Warrane College, University of New South Wales, NSW, 2033, Australia</aff>
        </contrib>
      </contrib-group>
      <volume>28</volume>
      <issue>4</issue>
      <fpage>1573</fpage>
      <lpage>1580</lpage>
      <pub-date date-type="pub">
        <day>12</day>
        <month>06</month>
        <year>2025</year>
      </pub-date>
      <abstract>
        <p>In this note we bring together in one place the recent extensions of telephone numbers using determinants from certain matrices. A common formula involving Hermite and relevant recurrence relations are given as part of this extension of the connections of these numbers with classical number theory.</p>
      </abstract>
      <kwd-group>
        <kwd>Telephone numbers</kwd>
        <kwd>Recurrence relation</kwd>
        <kwd>Determinant</kwd>
        <kwd>Matrices</kwd>
        <kwd>Hermite polynomials</kwd>
      </kwd-group>
      <custom-meta-group>
        <custom-meta>
          <meta-name>access</meta-name>
          <meta-value>open</meta-value>
        </custom-meta>
        <custom-meta>
          <meta-name>retracted</meta-name>
          <meta-value>no</meta-value>
        </custom-meta>
      </custom-meta-group>
    </article-meta>
  </front>
</article>
