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 A032750 #19 Feb 16 2025 08:32:36
%S A032750 131,181,333,454,919,969,1331,1881,3333,6556,9119,9669,10301,10501,
%T A032750 10601,10701,13031,13131,13231,13331,13431,13531,13631,13731,13831,
%U A032750 13931,14541,16161,16761,18081,18181,18281,18381,18481,18581,18681
%N A032750 Palindromic Super-2 Numbers.
%D A032750 C. A. Pickover, "Keys to Infinity", New York: Wiley, p. 7, 1995.
%H A032750 Harvey P. Dale, <a href="/A032750/b032750.txt">Table of n, a(n) for n = 1..1000</a>
%H A032750 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Super-dNumber.html">Super-d Number</a>.
%t A032750 stpQ[n_]:=Module[{idn=IntegerDigits[n],id2=IntegerDigits[2n^2]}, MemberQ[ Partition[id2,2,1],{2,2}]&&idn==Reverse[idn]]; Select[Range[20000],stpQ] (* _Harvey P. Dale_, Jan 16 2013 *)
%Y A032750 Cf. A014569, A032743.
%K A032750 nonn,base
%O A032750 1,1
%A A032750 _Patrick De Geest_, May 15 1998