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 A117281 #17 Aug 01 2019 01:26:08 %S A117281 252,2772,20502,23632,25452,26962,27972,48384,225522,252252,259952, %T A117281 279972,619916,1113111,1226221,1357531,2005002,2070702,2126212, %U A117281 2150512,2216122,2226222,2249422,2275722,2316132,2347432,2386832,2429242 %N A117281 Palindromes whose squares belong to A066531. %C A117281 a(n)^2 = A083408(k) for some k. %H A117281 Chai Wah Wu, <a href="/A117281/b117281.txt">Table of n, a(n) for n = 1..4679</a> (n = 1..54 from Hans Havermann) %H A117281 Shyam Sunder Gupta, <a href="http://www.shyamsundergupta.com/eporns.htm">EPRNs</a> %e A117281 27972 is in the sequence because 782432784 = 27972*27972 = 15984*48951. %e A117281 1113111 is in the sequence because 1239016098321 = 1113111*1113111 = 1022121*1212201. %Y A117281 Cf. A066531, A083408 (square EPRNs), A206642. %K A117281 nonn,base %O A117281 1,1 %A A117281 _Lekraj Beedassy_, Apr 23 2006 %E A117281 Edited and corrected by _Klaus Brockhaus_, Aug 21 2007 %E A117281 Edited by _N. J. A. Sloane_, Aug 01 2019