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 A061359 #8 Feb 11 2023 20:32:45 %S A061359 1,8,16,146,22086,31071113326,365107058344463715696, %T A061359 2684967738644586785227227090233956040549004, %U A061359 809079884187716191997158821357206898310718837487307207657194711477350102495950972665 %N A061359 a(1) = 1; a(n) = least number such that the concatenation a(n)a(n-1)...a(2)a(1) is a square. %H A061359 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a061/A061359.java">Java program</a> (github) %e A061359 a(3)a(2)a(1) = 1681 = 41^2, a(4)a(3)a(2)a(1) = 1461681 = 1209^2. %Y A061359 Cf. A050634, A050635. %K A061359 nonn,base %O A061359 1,2 %A A061359 _Amarnath Murthy_, Apr 28 2001 %E A061359 Corrected and extended by Larry Reeves (larryr(AT)acm.org), May 07 2001 %E A061359 More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001