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 A175440 #5 Oct 15 2013 10:07:49 %S A175440 9,33,48,66,87,99,117,216,273,288,297,333,484,513,528,666,783,819,999, %T A175440 1323,1331,1452,1474,1602,2178,2622,3333,4884,4961,6666,7161,7575, %U A175440 9999,10989,11979,12969,14652,14733,15972,20402,21021,21534,21648,23331 %N A175440 Terms in A177950 that are not in A002778. %C A175440 Terms n in A177950 such that n^2 is palindrome are also in A002778. %C A175440 This sequence consists of numbers (more interesting?) that are in A177950 but not in A002778. %C A175440 Notice that most terms are multiples of 3, while some are not: 484, 1331, 1474, 4961, 20402, 48884, 122221, 188887, 217822, 467126, 477773, 484484, 506506, 525503, 718189, 808808, 1461262, 1729408, 2004002, 2317315, 2920819, 4840484. %H A175440 Zak Seidov, <a href="http://zak08.livejournal.com/21500.html">A175440</a> %Y A175440 Cf. A002778 Numbers whose square is a palindrome, A177950 Numbers n dividing n^2 with digits reversed. %K A175440 base,nonn %O A175440 1,1 %A A175440 _Zak Seidov_, May 16 2010