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 A168039 #5 Sep 25 2013 03:06:02 %S A168039 0,4,4,9,9,16,16,25,25,25,25,36,36,36,36,49,49,49,49,64,64,64,64,64, %T A168039 64,81,81,81,81,81,81,100,100,100,100,100,100,121,121,121,121,121,121, %U A168039 121,121,144,144,144,144,144,144,144,144,169,169,169,169,169,169,169,169 %N A168039 Squares closest to 3*n. %H A168039 Vincenzo Librandi, <a href="/A168039/b168039.txt">Table of n, a(n) for n = 0..1000</a> %t A168039 Round[Sqrt[3*Range[0,120]]]^2 %Y A168039 Cf. A168038. %K A168039 nonn %O A168039 0,2 %A A168039 _Zak Seidov_, Nov 17 2009