PalindromicNumber 2006-05-27 15:56:40 2006-05-27 15:56:40 Definition % this is the default PlanetMath preamble. as your knowledge % of TeX increases, you will probably want to edit this, but % it should be fine as is for beginners. % almost certainly you want these \usepackage{amssymb} \usepackage{amsmath} \usepackage{amsfonts} % used for TeXing text within eps files %\usepackage{psfrag} % need this for including graphics (\includegraphics) %\usepackage{graphicx} % for neatly defining theorems and propositions %\usepackage{amsthm} % making logically defined graphics %\usepackage{xypic} % there are many more packages, add them here as you need them % define commands here An integer $n$ that in a given base $b$ is a palindrome. Given $n$ being $k$ digits $d_x$ long in base $b$, its value being $$n = \sum_{i = 0}^{k - 1} d_kb^i$$ then if the equalities $d_k = d_1$, $d_{k - 1} = d_2$, etc., hold, then $n$ is a {\em palindromic number}. There are infinitely many palindromic numbers in any given base.