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 A061661 #12 Aug 25 2023 00:58:29 %S A061661 30,210,1470,10290,10652,11636,53544,53730,59130,64896,72030,74564, %T A061661 81452,93510,94356,94400,97038,113754,348540,364016,374808,375204, %U A061661 376110,378642,413910,420848,454272,476352,479642,483428,485460,488232,503648,504210,516302 %N A061661 Numbers k > 1 such that, in base 7, k and k^2 contain the same digits in the same proportion. %H A061661 Ray Chandler, <a href="/A061661/b061661.txt">Table of n, a(n) for n = 1..1000</a> %e A061661 30 = 42_7 and 30^2 = 2424_7. %Y A061661 Cf. A061656, A061657, A061658, A061659, A061660, A061662, A061663, A114258, A061664. %K A061661 base,easy,nonn %O A061661 1,1 %A A061661 _Erich Friedman_, Jun 16 2001 %E A061661 More terms from _Naohiro Nomoto_, Oct 04 2001 %E A061661 Offset changed to 1 by _Alois P. Heinz_, May 10 2015