This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A057107 #9 Aug 11 2024 14:41:33 %S A057107 0,1,8,8008,120232021,124060421,161656161,185464581,544721127445, %T A057107 616947749616,3333169613333,3333802083333,6506939396056, %U A057107 12212500521221,5466543663456645,3310988011108890133,520752145595541257025,336753352502205253357633 %N A057107 Octagonal palindromes. %H A057107 Robert Price, <a href="/A057107/b057107.txt">Table of n, a(n) for n = 1..23</a> %H A057107 P. De Geest, <a href="https://www.worldofnumbers.com/octa.htm">Palindromic Octagonals</a> %t A057107 Select[PolygonalNumber[8, Range[0, 10^5]], PalindromeQ] (* _Robert Price_, Apr 29 2019 *) %Y A057107 Cf. A057106, A000567. %K A057107 nonn,base %O A057107 1,3 %A A057107 _Patrick De Geest_, Aug 15 2000 %E A057107 a(1)=0 added by _Robert Price_, Apr 29 2019