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 A006029 #21 Mar 01 2022 07:26:03 %S A006029 1,2,17,21,336 %N A006029 Numbers k such that the k-th tetrahedral number k*(k+1)*(k+2)/6 is palindromic. %C A006029 No more terms to 10^10. - _Charles R Greathouse IV_, Mar 23 2011 %H A006029 Patrick De Geest, <a href="http://www.worldofnumbers.com/tetra.htm">Palindromic Tetrahedrals</a> %t A006029 Select[Range[350],PalindromeQ[(#(#+1)(#+2))/6]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Apr 02 2018 *) %Y A006029 Cf. A006030. %K A006029 nonn,base,more %O A006029 1,2 %A A006029 _Patrick De Geest_