palindromic number

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

$$n=\sum _{i=0}^{k-1}{d}_k{b}^i$$

then if the equalities $d_k=d_1$, $d_{k-1}=d_2$, etc., hold, then $n$ is a palindromic number. There are infinitely many palindromic numbers in any given base.