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 A057106 #11 Aug 11 2024 14:41:33 %S A057106 0,1,2,52,6331,6431,7341,7863,426115,453486,1054067,1054167,1472746, %T A057106 2017631,42687015,1050553507,13175129925,335038979077,1400295262095, %U A057106 5847307263801,51722791547842,78849864240621,105802560494387 %N A057106 Numbers k such that k(3k-2) is an octagonal palindrome. %H A057106 P. De Geest, <a href="https://www.worldofnumbers.com/octa.htm">Palindromic Octagonals</a> %t A057106 Select[Range[0, 10^5], PalindromeQ[PolygonalNumber[8, #]] &] (* _Robert Price_, Apr 29 2019 *) %Y A057106 Cf. A057107, A000567. %K A057106 nonn,base %O A057106 1,3 %A A057106 _Patrick De Geest_, Aug 15 2000 %E A057106 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 17 2008 %E A057106 a(1)=0 added by _Robert Price_, Apr 29 2019