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 A076443 #11 Aug 26 2021 18:00:19
%S A076443 1331,698896,1003003001,637832238736,1000030000300001,
%T A076443 1033394994933301,1331399339931331,4099923883299904,
%U A076443 1000000300000030000001,1003303931991393033001,1030331909339091330301,1331003993003993001331,6916103777337773016196
%N A076443 Even-digit palindromic perfect powers.
%H A076443 Chai Wah Wu, <a href="/A076443/b076443.txt">Table of n, a(n) for n = 1..40</a>
%e A076443 a(1) = 11^3; a(2) = (4*11*19)^2; a(3) = (7*11*13)^3; a(4) = (4*7*11*2593)^2; a(5) = (11*9091)^3, a(6) = (7*11*13*101)^3, a(7) = (11*73*137)^3, etc.
%t A076443 a = {}; Do[ q = IntegerDigits[n]; p = FromDigits[ Join[q, Reverse[q]]]; If[ Apply[ GCD, Last[ Transpose[ FactorInteger[p]]]] > 1, a = Append[a, p]; Print[p]], {n, 1, 4000000}]
%Y A076443 Cf. A001597, A075786.
%K A076443 base,nonn
%O A076443 1,1
%A A076443 _Robert G. Wilson v_, Oct 12 2002
%E A076443 a(8)-a(13) from _Donovan Johnson_, Oct 03 2011