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 A206642 #9 Aug 01 2019 01:27:20 %S A206642 660,2520,4030,5040,6600,8160,25200,27720,32670,40300,43560,50400, %T A206642 66000,81600,205020,229320,236320,254520,269620,277200,279720,310030, %U A206642 326700,329670,351430,410040,435600,439560,458640,483840,486160 %N A206642 Non-palindromes whose squares are in A066531. %H A206642 Shyam Sunder Gupta, <a href="http://www.shyamsundergupta.com/eporns.htm">EPRNs</a> %e A206642 660 is in the sequence because 660^2 = 528*825 = 6600*0066; 2520 is in the sequence because 2520^2 = 14400*00441 = 25200*00252 = 44100*00144; etc. %Y A206642 Cf. A066531, A083408 (square EPRNs), A117281 (palindromic version). %K A206642 nonn,base %O A206642 1,1 %A A206642 _Hans Havermann_, Feb 11 2012 %E A206642 Edited by _N. J. A. Sloane_, Aug 01 2019