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 A167039 #12 Mar 15 2024 02:24:12 %S A167039 625,62500,6250000,58140625,625000000,5814062500,6703515625, %T A167039 62500000000,581406250000,670351562500,6250000000000,58140625000000, %U A167039 67035156250000,539545791015625,625000000000000,5814062500000000,6703515625000000,53954579101562500 %N A167039 Squares that remain squares when prefixed with a 5. %C A167039 Numbers s of A000290 such that 5*10^A055642(s)+s is also in A000290. %H A167039 Chai Wah Wu, <a href="/A167039/b167039.txt">Table of n, a(n) for n = 1..1000</a> %e A167039 625 = 25^2 is a square and becomes the square 5625 = 75^2 if a 5 is attached in front of its decimal representation. %K A167039 nonn,base %O A167039 1,1 %A A167039 _Claudio Meller_, Oct 27 2009 %E A167039 Keyword:base added by _R. J. Mathar_, Oct 28 2009 %E A167039 More terms from _Chai Wah Wu_, Sep 11 2014